Tüm alıştırma soruları

5215 soru

Tüm türler5,215 Çoktan seçmeli2,665 Çoklu seçim6 Doğru / Yanlış260 Sayısal512 Eşleştirme930 Sıralama396 Boşluk doldurma397 Kısa cevap49

Soru 1801Soru →

A fisherman holds an $8\text{-foot}$ fishing rod. He rests the base of the rod against his waist, which acts as the pivot point (fulcrum). His upper hand pulls upward on the rod at a distance of $2\text{ feet}$ from his waist. If a fish pulls downward on the tip of the rod with a force of $20\text{ lbs}$ , what is the required effort force applied by his upper hand to keep the rod balanced, and which class of lever does this represent? (Assume the weight of the rod is negligible).

80\text{ lbs}

; Third-class lever

5\text{ lbs}

; Third-class lever

60\text{ lbs}

; First-class lever

80\text{ lbs}

; Second-class lever

Cevabı ve açıklamayı göster

Cevap: $80\text{ lbs}$ ; Third-class lever

Cevap

The required effort force is

80\text{ lbs}

, and the fishing rod acts as a Third-class lever.

In this scenario, the effort (the upper hand) is located between the fulcrum (the waist) and the load (the fish). This specific arrangement defines a third-class lever. To find the required effort force, set up a torque balance equation:

\text{Effort Force} \times \text{Effort Distance} = \text{Load Force} \times \text{Load Distance}

. Substituting the given values yields

\text{Effort Force} \times 2\text{ ft} = 20\text{ lbs} \times 8\text{ ft}

. Solving for the effort force gives

160 / 2 = 80\text{ lbs}

Adım Adım Çözüm

Identify the locations of the fulcrum, effort, and load on the rod.

The fulcrum is at the base (waist), the effort is applied

2\text{ feet}

from the base, and the load is at the tip,

8\text{ feet}

from the base.

Establishing the sequence and distances of these points is necessary to determine the lever class and torque equations.

Determine the class of the lever.

It is a Third-class lever.

Because the effort force (upper hand) is located between the fulcrum (waist) and the load (fish).

Set up the torque balance equation.

\text{Effort Force} \times 2\text{ ft} = 20\text{ lbs} \times 8\text{ ft}

For the lever to be in equilibrium, the torque from the effort must equal the torque from the load.

Solve the equation for the effort force.

\text{Effort Force} \times 2 = 160

, so

\text{Effort Force} = 80\text{ lbs}

To find the specific pulling force the fisherman must exert.

Anahtar Kavram

Torque balance and Third-class levers

Soru 1802Soru →

A small metal anchor weighs $120 \text{ N}$ in the air. When the anchor is completely submerged in water, the tension on its lifting cable is measured to be $85 \text{ N}$ . What is the magnitude of the buoyant force acting on the submerged anchor?

Cevabı ve açıklamayı göster

Cevap: 35

Cevap

According to Archimedes' principle, the upward buoyant force exerted on a submerged object reduces its apparent weight. The buoyant force is equal to the difference between its true weight in the air and its apparent weight in the fluid. Subtracting the apparent weight (85 N) from the true weight (120 N) gives a buoyant force of 35 N.

Adım Adım Çözüm

Identify the actual weight and the apparent weight.

Actual weight = 120 N, Apparent weight = 85 N

These values represent the downward force of gravity and the net downward force when submerged, respectively.

Calculate the buoyant force.

120 N - 85 N = 35 N

The buoyant force is the upward force that accounts for the reduction in weight. It is found by subtracting the apparent weight from the actual weight.

Anahtar Kavram

Apparent Weight and Buoyant Force

Soru 1803Soru →

In mechanical assemblies, different methods are used to join components based on whether the connection needs to be permanent or removable. Match each common fastener or joint type with its correct description.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

Rivet matches with the non-threaded deformed fastener. Bolt and nut matches with the threaded, removable system. Cotter pin matches with the split wire used for prevention of loosening. Welded joint matches with the connection created by melting base materials.

Each mechanical fastener type has distinct physical characteristics and use cases. Welded joints fuse materials permanently through heat. Rivets are permanent mechanical pins that are deformed to lock pieces in place. Bolts and nuts are threaded, allowing them to be tightened and removed. Cotter pins act as secondary locking devices by passing through a hole to prevent primary fasteners from backing out.

Adım Adım Çözüm

Separate the listed items into permanent and removable joining methods.

Rivets and welded joints are permanent. Bolts/nuts and cotter pins are removable.

Categorizing the items simplifies the matching process by narrowing down the possible descriptions.

Evaluate the descriptions for the permanent methods.

The description mentioning 'melting and fusing' refers to a Welded joint. The description mentioning a 'non-threaded fastener that is physically deformed' refers to a Rivet.

Understanding the physical application of permanent joints differentiates thermal bonding (welding) from mechanical locking (riveting).

Evaluate the descriptions for the removable methods.

The description mentioning a 'threaded, removable fastening system' accurately describes a Bolt and nut. The description detailing a 'split wire inserted through a hole' describes a Cotter pin.

This isolates the primary structural fastener (bolt) from the secondary security device (cotter pin).

Anahtar Kavram

Characteristics and basic applications of mechanical fasteners and joints

Tahmini Süre:45s

Soru 1804Soru →

A naval torpedo with a mass of $1,200 \text{ kg}$ is fired from a submarine. If the propulsion system generates a constant net forward force of $6,000 \text{ N}$ , what is the forward acceleration of the torpedo?

0.2 \text{ m/s}^2

0.5 \text{ m/s}^2

5.0 \text{ m/s}^2

50.0 \text{ m/s}^2

Cevabı ve açıklamayı göster

Cevap: $5.0 \text{ m/s}^2$

Cevap

The correct answer is

5.0 \text{ m/s}^2

According to Newton's Second Law (

F = ma

), acceleration is calculated by dividing the net force by the mass. Dividing

6,000 \text{ N}

1,200 \text{ kg}

yields

5.0 \text{ m/s}^2

Adım Adım Çözüm

Identify the given values from the problem statement.

Mass (

m

) =

1,200 \text{ kg}

, Net Force (

F

) =

6,000 \text{ N}

Extracting the known variables is necessary to apply the correct physics formula.

Apply Newton's Second Law of Motion.

The formula is

F = ma

. Rearranging to solve for acceleration gives

a = \frac{F}{m}

Newton's Second Law relates force, mass, and acceleration.

Substitute the values into the formula and solve.

a = \frac{6000}{1200} = 5.0 \text{ m/s}^2

Dividing the net force by the mass computes the resulting acceleration.

Anahtar Kavram

Newton's Second Law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (

F = ma

Soru 1805Soru →

A technician is mounting a sensitive metal control panel to a high-temperature industrial furnace using solid steel standoff bolts. To minimize the rate of heat conducted directly through these bolts to the control panel, which design modification is most effective?

Use longer standoff bolts with a smaller cross-sectional area.

Polish the exterior of the bolts to a highly reflective finish to bounce the heat back into the furnace.

Choose a bolt material with a lower specific heat capacity so that the metal requires more energy to heat up.

Shorten and widen the bolts so the increased metal mass can physically block the transfer of thermal energy.

Cevabı ve açıklamayı göster

Cevap: Use longer standoff bolts with a smaller cross-sectional area.

Cevap

Use longer standoff bolts with a smaller cross-sectional area.

The rate of conductive heat transfer through a solid object depends heavily on its geometry. It is directly proportional to the cross-sectional area and inversely proportional to the length. By using longer bolts with a smaller cross-sectional area, you increase the thermal resistance of the connection, which significantly reduces the amount of heat that reaches the control panel.

Adım Adım Çözüm

Identify the primary mechanism of heat transfer in the scenario.

The heat is traveling through solid steel bolts that directly connect a hot object to a cooler one, which means the mechanism is thermal conduction.

Understanding the heat transfer mode is necessary to apply the correct physical principles.

Recall the factors that affect the rate of thermal conduction.

According to Fourier's Law of Thermal Conduction, the rate of heat transfer (

Q/t

) is directly proportional to the cross-sectional area (

A

) and inversely proportional to the length (

L

) of the conductor.

This relationship determines how geometric changes will impact heat flow.

Determine the geometric changes required to minimize the heat transfer rate.

To decrease the heat transfer rate, the thermal resistance must be increased by minimizing the cross-sectional area (making the bolts thinner) and maximizing the length (making the bolts longer).

A smaller pathway over a longer distance restricts the flow of thermal energy through the solid.

Anahtar Kavram

Fourier's Law of Thermal Conduction

Soru 1806Soru →

A heavy winch is dragging a $200\text{ kg}$ rectangular steel block across a flat, horizontal concrete surface at a constant velocity of $5\text{ m/s}$ . The coefficient of kinetic friction between the steel and the concrete is $0.4$ . (Assume gravitational acceleration $g = 10\text{ m/s}^2$ ). What is the approximate kinetic frictional force opposing the block's motion, and how would this force change if the block were turned to slide on a face with only half the original surface area?

800\text{ N}

; the frictional force would remain exactly the same.

80\text{ N}

; the frictional force would remain exactly the same.

800\text{ N}

; the frictional force would be halved.

1,000\text{ N}

; the frictional force would remain exactly the same.

Cevabı ve açıklamayı göster

Cevap: $800\text{ N}$ ; the frictional force would remain exactly the same.

Cevap

The kinetic frictional force is

800\text{ N}

, and it would remain exactly the same if the surface area were halved.

The correct answer accurately calculates the normal force by multiplying mass and gravity (

200 \times 10 = 2000\text{ N}

), then applies the friction coefficient (

2000 \times 0.4 = 800\text{ N}

). Furthermore, it correctly applies the principle that sliding friction is unaffected by the size of the contact area, so the force remains constant regardless of which face the block slides on.

Adım Adım Çözüm

Calculate the weight (which equals the normal force) of the block.

W = mg = 200\text{ kg} \times 10\text{ m/s}^2 = 2000\text{ N}

. Since the surface is horizontal, the normal force

N = 2000\text{ N}

Kinetic friction is directly proportional to the normal force pressing the surfaces together.

Calculate the kinetic frictional force.

F_k = \mu_k \times N = 0.4 \times 2000\text{ N} = 800\text{ N}

The formula for kinetic friction requires multiplying the normal force by the coefficient of kinetic friction.

Evaluate the effect of changing the surface area.

The frictional force remains

800\text{ N}

Amontons' Second Law of Friction states that the force of friction is independent of the apparent area of contact. The pressure increases on the smaller area, but the total normal force remains unchanged.

Anahtar Kavram

Kinetic friction depends solely on the normal force and the materials in contact (coefficient of friction), and is completely independent of the contact surface area and velocity.

Soru 1807Soru →

Arrange the following stages of a natural convection loop in the correct chronological order, starting from the moment a home baseboard radiator is turned on.

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct sequence is: Air absorbs heat and expands -> Warm air rises -> Air cools across the room -> Cooler air sinks to the floor.

A natural convection loop is driven entirely by continuous changes in fluid density caused by temperature differences. Heating the fluid decreases its density, causing it to rise via buoyancy. As the fluid circulates away from the heat source, it cools, increases in density, and sinks, creating a continuous physical circulation pattern.

Adım Adım Çözüm

Identify the initial thermal interaction.

The air immediately surrounding the radiator absorbs heat and expands.

Convection loops begin with localized heating, which changes the density of the fluid.

Apply the principle of thermal buoyancy.

The heated, expanded air rises.

Fluids that are less dense than their surroundings will always rise due to buoyancy.

Determine what happens as the fluid moves away from the heat source.

The air loses heat to the room, cools down, and contracts (becomes more dense).

Without a continuous heat source, the warm air naturally dissipates its heat to the cooler environment.

Complete the circulation cycle.

The cooled, denser air sinks to the floor and moves back toward the radiator.

Gravity pulls the denser air downward, filling the void left by the newly heated air rising from the radiator.

Anahtar Kavram

Density-driven natural convection loops

Tahmini Süre:45s

Soru 1808Soru →

A vertical communications mast features a rigid horizontal steel cross-arm extending outward to support a heavy dish antenna at its far end. To support the load, a diagonal steel cable connects the outer tip of the cross-arm to an anchor point higher up on the main mast. Assuming the weight of the cross-arm itself is negligible compared to the antenna, which of the following best describes the primary internal forces experienced by these two structural components?

The cross-arm experiences compression, and the diagonal cable experiences tension.

The cross-arm experiences tension, and the diagonal cable experiences compression.

Both the cross-arm and the diagonal cable experience tension.

The cross-arm experiences bending, and the diagonal cable experiences shear.

Cevabı ve açıklamayı göster

Cevap: The cross-arm experiences compression, and the diagonal cable experiences tension.

Cevap

The cross-arm experiences compression, and the diagonal cable experiences tension.

The correct answer accurately applies static equilibrium to the joint supporting the antenna. The heavy antenna pulls straight down. To counteract this, the diagonal cable must pull diagonally upward and inward toward its anchor point on the mast. Because the cable pulls on the joint, it is in tension. However, this inward pull from the cable would drag the antenna toward the mast if unopposed. The rigid horizontal cross-arm prevents this by pushing outward against the joint. Because the cross-arm is being squeezed between the mast and the inward-pulling cable, it is under compression.

Adım Adım Çözüm

Analyze the forces acting on the joint at the outer tip of the cross-arm.

There is a downward force from the weight of the antenna.

Identifying the applied external load is the first step in finding internal forces.

Determine how the diagonal cable responds to the downward load.

The cable must pull upward to prevent the antenna from falling. Since it attaches higher up on the mast, its pull is directed upward and inward along its length.

Cables can only pull (tension); they cannot push.

Resolve the cable's tension force into vertical and horizontal components.

The upward vertical component supports the antenna's weight. The horizontal component pulls the joint inward toward the mast.

Vector resolution helps determine the effect of the cable on the horizontal cross-arm.

Analyze the horizontal cross-arm's response to the cable's inward pull.

To keep the joint stationary (in equilibrium), the cross-arm must push outward against the inward pull of the cable. A member that pushes outward at its ends is under compression.

Newton's laws of motion dictate that all forces at a stationary joint must sum to zero.

Anahtar Kavram

Vector resolution and equilibrium in truss-like structures determine whether a member is in tension or compression.

Soru 1809Soru →

Match each wedge geometry or characteristic with its corresponding mechanical property or practical application.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

The correct matches align the high length-to-thickness wedge with high mechanical advantage, the low length-to-thickness wedge with low mechanical advantage, the single-beveled wedge with one-directional pushing, and the double-beveled wedge with symmetrical splitting.

Each wedge geometry dictates a specific mechanical trade-off. Long and narrow profiles maximize mechanical advantage to reduce required effort, while short and wide profiles sacrifice force multiplication for rapid, wide separation. Furthermore, the bevel symmetry determines the specific direction of the applied lateral splitting forces.

Adım Adım Çözüm

Evaluate the length-to-thickness ratios for mechanical advantage.

A high ratio means a long, thin wedge (high MA), while a low ratio means a short, thick wedge (low MA).

The ideal mechanical advantage for a wedge is calculated as the length of the wedge divided by its maximum thickness.

Evaluate the structural symmetry (bevel shapes).

A single-bevel focuses material displacement in one direction, while a double-bevel splits material evenly on both sides.

The physical symmetry of the wedge's inclined planes determines the direction of the output forces relative to the driving force.

Match the calculated geometries to their practical tool applications.

High ratio corresponds to high MA; low ratio corresponds to low MA; single-bevel corresponds to flush chiseling; double-bevel corresponds to log splitting.

Connecting theoretical physics principles to practical tool designs verifies the correct logical pairings.

Anahtar Kavram

Wedge Geometry and Mechanical Advantage

Soru 1810Soru →

A heavy-duty mechanical system uses a passive thermosiphon (natural convection loop) to cool its engine block without a mechanical pump. When the engine is first started from a completely cold state, arrange the following physical processes in the exact chronological sequence that initiates and sustains the continuous convection loop.

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct sequence begins with initial heat conduction, followed by thermal expansion, the downward pull of gravity on denser fluid, the upward displacement of the warmer fluid, and finally heat rejection to sustain the cycle.

This sequence accurately describes the mechanistic realities of a density-driven thermosiphon cycle. Heat must first be introduced to the fluid, which causes thermal expansion and a drop in localized density. This density difference allows gravity to exert a greater downward force on the heavier, colder fluid from the top of the system. As the colder fluid sinks, it mechanically displaces the lighter, warmer fluid, forcing it upward into the radiator. Finally, the warm fluid rejects its heat at the top, increasing its density once again to continuously drive the loop.

Adım Adım Çözüm

Identify the initial transfer of energy.

Thermal energy conducts into the fluid.

A convection loop requires an initial heat source to alter the fluid's thermodynamic state.

Determine the immediate physical effect of the added heat on the fluid.

The fluid expands and its density decreases.

Increased temperature causes thermal expansion, which changes the mass-to-volume ratio of the specific localized fluid.

Identify the primary physical force that initiates fluid movement.

Gravity pulls the heavier, cooler fluid downward.

Because the heated fluid is now less dense, gravity exerts a stronger downward force on the surrounding colder fluid, initiating a hydrostatic pressure differential.

Determine the resulting motion of the heated fluid.

The warm fluid is displaced and forced upward.

The sinking dense fluid must occupy the space at the bottom, mechanically pushing the lighter fluid upward through the system.

Identify the process that completes the closed loop.

The fluid cools at the heat sink, becomes dense, and sinks.

To maintain continuous flow, the fluid must lose its heat at the radiator so it can regain density and become the driving force for the next cycle.

Anahtar Kavram

Mechanisms of Natural Convection and Buoyancy-Driven Flow

Soru 1811Soru →

A high-power electrical transformer is submerged in a sealed tank of mineral oil to prevent overheating. The exterior of the tank features a series of hollow, vertical cooling tubes connected to the main tank at both the top and the bottom. If the system relies entirely on natural convection (without mechanical pumps) to circulate the fluid and dissipate heat, which of the following accurately describes the required flow path and its driving physical mechanism?

The heated oil expands and becomes less dense, rising to the top of the main tank and entering the upper openings of the cooling tubes; as it cools in the exterior tubes, it becomes denser and sinks, re-entering the main tank at the bottom.

The heat from the core decreases the total mass of the surrounding oil, reducing its weight and causing it to be displaced upward by heavier oil, which then forces the lighter oil downward through the cooling tubes.

The heated oil contracts near the transformer core, becoming denser and sinking to the bottom of the tank, which displaces cooler oil and forces it up through the external tubes to dissipate accumulated heat at the top.

The oil remains mostly stationary inside the tank while thermal energy conducts from molecule to molecule outward into the cooling tubes, heating the exterior metal which then creates an upward draft of cold air.

Cevabı ve açıklamayı göster

Cevap: The heated oil expands and becomes less dense, rising to the top of the main tank and entering the upper openings of the cooling tubes; as it cools in the exterior tubes, it becomes denser and sinks, re-entering the main tank at the bottom.

Cevap

The heated oil expands, becomes less dense, rises to the top of the tank, enters the top of the cooling tubes, cools/sinks, and returns to the bottom of the tank.

In a natural convection loop, the heat source must be located physically lower than the cooling area to maintain circulation. The oil heated by the transformer core expands, its density decreases, and it rises to the top of the tank. To dissipate heat, it must flow into the upper ends of the cooling radiators. As it sheds heat to the environment, it cools, contracts, becomes denser, and gravity pulls it down through the tubes. It then re-enters the bottom of the main tank to replace the oil that is rising, creating a continuous, self-sustaining flow.

Adım Adım Çözüm

Identify the primary mechanism of heat transfer in a fluid system without pumps.

The mechanism is natural convection.

Natural convection is driven entirely by density differences caused by temperature changes within the fluid.

Determine how the heat from the transformer core affects the surrounding mineral oil.

The oil absorbs heat, expands in volume, and its density decreases.

Thermal expansion causes molecules to move further apart, lowering the mass per unit volume.

Trace the path of the heated, less dense oil.

It experiences an upward buoyant force, rising to the highest available point inside the main tank.

Less dense fluids rise above denser fluids due to gravity.

Trace the path of the oil as it interacts with the exterior cooling tubes.

The hot oil enters the upper connections of the exterior tubes. As it dissipates heat to the outside air, it cools, its density increases, and it sinks down the tubes to re-enter the main tank at the bottom.

This completes the continuous circulation loop required for sustained natural convection.

Anahtar Kavram

Natural convection relies on a continuous loop where a fluid is heated (becoming less dense and rising), moves to a cooler area to dissipate heat (becoming denser and sinking), and returns to the heat source.

Soru 1812Soru →

Match each real-world circular motion scenario with the correct mechanical principle or force description that governs it.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

The correct matches align specific real-world mechanical scenarios with the physical principles governing circular motion, inertia, and force vectors.

In circular motion, centripetal force is the required net inward force that keeps an object moving in a curve. The source of this force varies depending on the scenario (e.g., friction on a flat road, or normal force at the bottom of a loop). If this force is removed, the object follows a tangential path due to inertia. The outward 'centrifugal' sensation is not a true force, but rather the effect of inertia resisting a change in direction.

Adım Adım Çözüm

Analyze the snapped cable scenario (left_1).

Matches with tangential path (right_2).

When a centripetal force is suddenly removed, inertia dictates that the object travels straight along the tangent line of the curve.

Analyze the flat curve scenario (left_2).

Matches with static friction (right_1).

Without banking to provide a normal force component, friction is the only lateral force capable of directing the vehicle toward the center of curvature.

Analyze the passenger turning scenario (left_3).

Matches with inertia and fictitious outward force (right_4).

The sensation of being thrown outward is actually the body's inertia attempting to travel straight while the vehicle accelerates inward.

Analyze the vertical dive pull-out scenario (left_4).

Matches with normal force exceeding gravity (right_3).

To create a net upward (center-pointing) force at the bottom of a dive, the upward normal force must support the aircraft's weight and provide the additional centripetal force.

Anahtar Kavram

Circular Motion and Centripetal Force

Soru 1813Soru →

An industrial cardboard baler utilizes a closed hydraulic system to compress recyclable materials. The system features an input pump piston with a cross-sectional area of $3 \text{ in}^2$ and a large output driving piston with a cross-sectional area of $45 \text{ in}^2$ . If the input piston is pushed downward for a single stroke distance of $15 \text{ inches}$ , how many inches will the output piston move? (Assume no fluid is lost and the fluid is incompressible.)

Cevabı ve açıklamayı göster

Cevap: 1

Cevap

In a hydraulic system, the volume of fluid displaced must be conserved. The output piston has 15 times the cross-sectional area of the input piston (

45 \div 3 = 15

). Because it is 15 times larger, it will only travel 1/15th of the distance to displace the identical volume of fluid. Therefore, an input distance of 15 inches results in an output distance of exactly 1 inch.

Adım Adım Çözüm

Identify the relationship for fluid displacement in a closed hydraulic system.

A_1 \times d_1 = A_2 \times d_2

Because liquids are incompressible, the volume of fluid pushed out by the input piston (

A_1 \times d_1

) must equal the volume of fluid pushing up the output piston (

A_2 \times d_2

Substitute the given values for the input piston (

A_1 = 3

d_1 = 15

) and output piston (

A_2 = 45

3 \times 15 = 45 \times d_2

This sets up the equation with all known variables to solve for the unknown distance (

d_2

Calculate the total volume displaced by the input piston.

45 = 45 \times d_2

Multiplying the input area by its travel distance gives a total displaced volume of 45 cubic inches.

Solve for the output distance (

d_2

) by dividing the total volume by the output piston's area.

d_2 = 1

Dividing 45 cubic inches by 45 square inches yields a travel distance of 1 inch.

Anahtar Kavram

Conservation of fluid volume and the distance-force tradeoff in hydraulics

Soru 1814Soru →

Match each physical concept or measuring instrument to its correct characteristic or function regarding mass and weight.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

Mass pairs with the constant fundamental property; Weight pairs with the gravity-dependent force; Double-pan balance pairs with the consistent standard-comparison device; Spring scale pairs with the coil-based device.

The correct pairings accurately reflect that mass is an invariant scalar quantity measured consistently by a balance, while weight is a vector force that depends on local gravity and is measured by a spring scale.

Adım Adım Çözüm

Distinguish between the conceptual definitions of mass and weight.

Mass is identified as a constant amount of matter, whereas weight is the variable force of gravity acting on that matter.

To correctly match the physical properties with their fundamental definitions.

Determine the operational principles of the two measuring instruments.

A double-pan balance compares masses directly and works consistently regardless of local gravity, whereas a spring scale measures downward force (weight) via coil stretch, which varies with gravity.

To correctly pair the measuring devices with their functional characteristics across different gravitational fields.

Anahtar Kavram

Mass is an invariant property measured by comparing it to known standards (using a balance), while weight is a location-dependent force measured by its effect on a spring (using a spring scale).

Soru 1815Soru →

Match each physical scenario with the magnitude of its resulting acceleration. Apply Newton's Second Law of Motion ( $F=ma$ ) and ensure you calculate the net force for each situation.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

The correct matches are: Transport vehicle maps to 2.0 m/s², Hovercraft maps to 3.0 m/s², Hoisted payload maps to 6.0 m/s², and Descending elevator maps to 4.0 m/s².

Each correct match is derived by first identifying all acting forces on the object, determining the net force (

F_{net}

), and then dividing by the mass (

a = F_{net}/m

). For horizontal motion, opposing forces (friction, drag) are subtracted from applied thrust. For vertical motion, the object's weight (

mg

) must be calculated and subtracted from the cable tension.

Adım Adım Çözüm

Calculate the acceleration for the transport vehicle.

Net force = 12,000 N - 2,000 N - 2,000 N = 8,000 N. Acceleration = 8,000 N / 4,000 kg = 2.0 m/s².

Forces acting in the opposite direction of motion (drag and friction) must be subtracted from the forward thrust.

Calculate the acceleration for the hovercraft.

Net force = (2 * 3,000 N) - 1,500 N = 4,500 N. Acceleration = 4,500 N / 1,500 kg = 3.0 m/s².

The total thrust from both propellers must be combined before subtracting the opposing water current.

Calculate the acceleration for the hoisted payload.

Weight = 500 kg * 10 m/s² = 5,000 N. Net upward force = 8,000 N - 5,000 N = 3,000 N. Acceleration = 3,000 N / 500 kg = 6.0 m/s².

In vertical motion, the downward force of gravity (weight) must be calculated and subtracted from the upward tension to find the net force.

Calculate the acceleration for the descending elevator.

Weight = 800 kg * 10 m/s² = 8,000 N. Net downward force = 8,000 N - 4,800 N = 3,200 N. Acceleration = 3,200 N / 800 kg = 4.0 m/s².

Because the elevator descends, the downward gravitational force exceeds the upward tension. Net force is weight minus tension.

Anahtar Kavram

Newton's Second Law of Motion (

F_{net} = ma

)

Soru 1816Soru →

A mechanic needs to move a heavy steel block across a flat concrete floor. Which of the following actions will successfully decrease the frictional resistance between the block and the floor?

Turning the block so it rests on its narrowest side to reduce the contact surface area

Placing round steel pipes underneath the block to act as rollers

Pressing downward on the top of the block while moving it to decrease its mass

Pushing the block with a sudden strike to eliminate the floor's opposing reaction force

Cevabı ve açıklamayı göster

Cevap: Placing round steel pipes underneath the block to act as rollers

Cevap

Placing round steel pipes underneath the block to act as rollers.

Rolling friction is significantly lower than sliding (kinetic) friction. By placing round steel pipes under the heavy block, the sliding motion is converted into a rolling motion, which drastically reduces the physical effort and resistance required to move the object.

Adım Adım Çözüm

Identify the type of friction currently acting on the block.

The block is sliding directly across the floor, so sliding (kinetic) friction is present.

Understanding the current resistance is necessary to evaluate ways to reduce it.

Evaluate the physical effect of each proposed action.

Changing surface area has no effect on friction magnitude. Pressing down increases friction. A sudden strike cannot eliminate reaction forces. Using pipes changes the friction type entirely.

Applying physical laws to each option isolates the effective method.

Compare the magnitude of sliding friction to rolling friction.

Rolling friction is significantly lower than sliding friction for heavy objects on hard surfaces.

This confirms that using pipes as rollers is the mechanically correct way to decrease resistance.

Anahtar Kavram

Friction and Resistance (Rolling vs. Sliding Friction)

Tahmini Süre:45s

Soru 1817Soru →

A shipwright uses a steel wedge to precisely align a heavy hull plate. The wedge has a length of $24\text{ cm}$ and a maximum heel thickness of $4\text{ cm}$ . If the shipwright strikes the heel, applying an average effort force of $600\text{ N}$ , what is the theoretical maximum lateral lifting force exerted by the wedge on the hull plate?

2400\text{ N}

100\text{ N}

3600\text{ N}

600\text{ N}

Cevabı ve açıklamayı göster

Cevap: $3600\text{ N}$

Cevap

3600\text{ N}

The mechanical advantage (IMA) of a wedge is calculated by dividing its length by its maximum thickness. In this case,

24\text{ cm} / 4\text{ cm} = 6

. The theoretical maximum lateral force is the effort force multiplied by the IMA, which is

600\text{ N} \times 6 = 3600\text{ N}

Adım Adım Çözüm

Calculate the ideal mechanical advantage (IMA) of the wedge.

IMA = \frac{24\text{ cm}}{4\text{ cm}} = 6

The IMA of a wedge is the ratio of its penetration length to its maximum thickness.

Calculate the theoretical maximum lateral force.

F_{\text{out}} = 6 \times 600\text{ N} = 3600\text{ N}

The output lateral force is the product of the applied effort force and the mechanical advantage.

Anahtar Kavram

The ideal mechanical advantage of a wedge is determined by the ratio of its length to its thickness.

Soru 1818Soru →

A theater stage crew needs to roll a heavy $400$ -pound lighting rig up to a stage platform that is $5$ feet high. They can build either a steep ramp that is $10$ feet long or a gentle ramp that is $20$ feet long. Assuming the ramp surfaces and wheels are perfectly frictionless, which of the following statements correctly compares the two ramp options?

The

20

-foot ramp reduces both the required effort force and the total work done by half compared to the

10

-foot ramp.

The

10

-foot ramp requires less total work than the

20

-foot ramp because the lighting rig is moved across a shorter total distance.

The

20

-foot ramp requires half the effort force of the

10

-foot ramp, but the total work done remains exactly the same for both.

The

20

-foot ramp requires less effort force because placing the rig on a shallower angle effectively reduces the mass of the rig.

Cevabı ve açıklamayı göster

Cevap: The $20$ -foot ramp requires half the effort force of the $10$ -foot ramp, but the total work done remains exactly the same for both.

Cevap

The

20

-foot ramp requires half the effort force of the

10

-foot ramp, but the total work done remains exactly the same for both.

The Ideal Mechanical Advantage (IMA) of an inclined plane is its length divided by its height. The

20

-foot ramp has an IMA of

4

(

20/5

), requiring

100

lbs of effort force. The

10

-foot ramp has an IMA of

2

(

10/5

), requiring

200

lbs of effort force. Therefore, the longer ramp requires half the effort force. However, because simple machines do not change the total amount of work done (

\text{Work} = \text{Force} \times \text{Distance}

), both ramps require

2000

ft-lbs of total work to lift the rig

5

feet vertically.

Adım Adım Çözüm

Calculate the Ideal Mechanical Advantage (IMA) for both ramps using the formula

IMA = \text{Length} / \text{Height}

Steep ramp IMA =

10 / 5 = 2

. Gentle ramp IMA =

20 / 5 = 4

IMA determines how much the inclined plane multiplies the input force.

Determine the required effort force for each ramp using the formula

\text{Effort} = \text{Load} / IMA

Steep ramp effort =

400 / 2 = 200

lbs. Gentle ramp effort =

400 / 4 = 100

lbs.

This mathematical relationship shows that the

20

-foot ramp requires exactly half the effort force of the

10

-foot ramp.

Calculate the total work done for both scenarios using

\text{Work} = \text{Force} \times \text{Distance}

(along the ramp).

Work for steep ramp =

200 \text{ lbs} \times 10 \text{ ft} = 2000 \text{ ft-lbs}

. Work for gentle ramp =

100 \text{ lbs} \times 20 \text{ ft} = 2000 \text{ ft-lbs}

This confirms the principle of conservation of energy: while simple machines alter the force required, they do not change the total work done against gravity.

Anahtar Kavram

Ideal Mechanical Advantage and the Work-Force Tradeoff

Soru 1819Soru →

A standard derrick crane lifts a heavy shipping container. The crane consists of a vertical rigid mast anchored to a ship's deck, a rigid steel boom extending outward and upward from the base of the mast, and a horizontal steel cable connecting the top of the mast to the upper tip of the boom. The container hangs vertically from the upper tip of the boom. Under the downward weight of the container, what primary internal structural forces are experienced by the horizontal steel cable and the rigid steel boom, respectively?

The horizontal cable experiences tension, and the rigid boom experiences compression.

The horizontal cable experiences compression, and the rigid boom experiences tension.

Both the horizontal cable and the rigid boom experience tension.

Both the horizontal cable and the rigid boom experience compression.

Cevabı ve açıklamayı göster

Cevap: The horizontal cable experiences tension, and the rigid boom experiences compression.

Cevap

The horizontal cable experiences tension, and the rigid boom experiences compression.

The correct answer accurately identifies that cables can only stretch (putting them in tension) to keep the structure from collapsing, while the rigid boom acts as a column holding up the weight, which squeezes it (putting it in compression).

Adım Adım Çözüm

Analyze the forces acting at the tip of the boom.

Three forces meet at the tip: the downward weight of the container, the horizontal force from the cable, and the angled force from the boom.

Identifying the junction point allows for force balancing (equilibrium).

Determine the state of the horizontal steel cable.

The cable prevents the boom from falling outward and downward. To hold the boom back, the cable must pull inward, meaning it is being stretched.

A stretched structural member is experiencing tension.

Determine the state of the rigid steel boom.

The boom pushes upward and outward against the downward pull of the load and the inward pull of the cable. The weight pushes down into the length of the boom.

A structural member that is being pushed or squeezed from its ends is experiencing compression.

Anahtar Kavram

Tension and Compression in Structural Members

Soru 1820Soru →

An astronaut floating motionless in space throws a heavy wrench directly forward. As a result, the astronaut is pushed backward. According to Newton's Third Law of Motion, what causes the astronaut to move backward?

The wrench exerts a backward force on the astronaut that is equal to the forward force applied to the wrench.

The astronaut's inertia acts in the opposite direction to resist the forward motion of the wrench.

The heavy mass of the astronaut generates a larger backward force than the wrench's forward force.

The sudden removal of the wrench's weight creates an imbalance that propels the astronaut backward.

Cevabı ve açıklamayı göster

Cevap: The wrench exerts a backward force on the astronaut that is equal to the forward force applied to the wrench.

Cevap

The wrench exerts an equal and opposite backward force on the astronaut.

Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. These forces always act on two different interacting bodies. When the astronaut (Body 1) applies a forward force to the wrench (Body 2), the wrench simultaneously applies a backward force of exactly the same magnitude to the astronaut. This equal and opposite push is what causes the astronaut to move backward.

Adım Adım Çözüm

Identify the initial action force described in the scenario.

The action force is the astronaut's hand pushing the heavy wrench forward.

To apply Newton's Third Law, the first interacting body and its applied force must be defined.

Apply Newton's Third Law of Motion to find the reaction force.

For the forward force on the wrench, there must be an equal and opposite backward force.

Newton's Third Law dictates that every action has an equal and opposite reaction occurring on the other interacting body.

Determine which object applies this reaction force to the astronaut.

The wrench applies the backward force onto the astronaut.

Forces in a Third Law pair always act on opposite objects: Astronaut pushes Wrench, therefore Wrench pushes Astronaut.

Anahtar Kavram

Newton's Third Law (Action/Reaction)

Tahmini Süre:45s

ÖncekiSayfa 91 / 261Sonraki

Tüm alıştırma soruları

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Cevap

Adım Adım Çözüm

Anahtar Kavram