Tüm alıştırma soruları

13931 soru

Soru 3561Soru

Match each chemical compound or process related to water hardness with its correct description or function.

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Öğeler

Calcium hydrogencarbonate (Ca(HCO3)2\text{Ca(HCO}_3\text{)}_2)
Calcium tetraoxosulfate(VI) (CaSO4\text{CaSO}_4)
Boiling
Addition of washing soda (Na2CO3\text{Na}_2\text{CO}_3)

Eşleşmeler

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Cevap

Calcium hydrogencarbonate matches with causes temporary hardness; Calcium tetraoxosulfate(VI) matches with causes permanent hardness; Boiling matches with removes temporary hardness only; Addition of washing soda matches with removes both temporary and permanent hardness.
Calcium hydrogencarbonate is soluble and decomposes upon heating to form insoluble calcium carbonate, causing temporary hardness. Calcium tetraoxosulfate(VI) stays dissolved when boiled, causing permanent hardness. Boiling specifically precipitates temporary hardness salts. Washing soda contains carbonate ions which precipitate calcium ions from both hydrogencarbonates and sulfates, removing both temporary and permanent hardness.

Adım Adım Çözüm

1
Identify the cause of temporary hardness
Calcium hydrogencarbonate (Ca(HCO3)2\text{Ca(HCO}_3\text{)}_2) causes temporary hardness because it thermally decomposes when heated.
Temporary hardness is due to soluble hydrogen trioxocarbonates of calcium and magnesium.
2
Identify the cause of permanent hardness
Calcium tetraoxosulfate(VI) (CaSO4\text{CaSO}_4) causes permanent hardness because boiling does not precipitate it.
Permanent hardness is due to soluble sulfates and chlorides of calcium and magnesium.
3
Determine the effect of boiling
Boiling removes temporary hardness by converting dissolved hydrogencarbonates into insoluble calcium carbonate precipitate.
Thermal decomposition: Ca(HCO3)2(aq)CaCO3(s)+H2O(l)+CO2(g)\text{Ca(HCO}_3\text{)}_2\text{(aq)} \rightarrow \text{CaCO}_3\text{(s)} + \text{H}_2\text{O(l)} + \text{CO}_2\text{(g)}.
4
Determine the effect of adding washing soda
Washing soda (Na2CO3\text{Na}_2\text{CO}_3) removes both temporary and permanent hardness.
Carbonate ions precipitate Ca2+\text{Ca}^{2+} ions as CaCO3(s)\text{CaCO}_3\text{(s)} regardless of whether they originated from hydrogencarbonate or sulfate salts.

Anahtar Kavram

Causes, types, and chemical methods for removal of water hardness
Tahmini Süre:45s
Soru 3562Soru

In the reaction between octasulfur, S8S_8, and concentrated trioxonitrate(V) acid, sulfur is oxidized to tetraoxosulfate(VI) acid, H2SO4H_2SO_4. What are the oxidation numbers of sulfur in S8S_8 and H2SO4H_2SO_4 respectively?

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Cevap: 00 and +6+6

Cevap

The oxidation numbers of sulfur in S8S_8 and H2SO4H_2SO_4 are 00 and +6+6 respectively.
Free uncombined elements carry an oxidation state of zero, so sulfur in S8S_8 is 00. In tetraoxosulfate(VI) acid (H2SO4H_2SO_4), setting the neutral molecule oxidation sum to zero yields 2(+1)+S+4(2)=02(+1) + S + 4(-2) = 0, giving S=+6S = +6.

Adım Adım Çözüm

1
Determine the oxidation state of sulfur in free elemental form (S8S_8).
Oxidation state of sulfur in S8=0S_8 = 0.
By definition, an element in its free or uncombined state has an oxidation state of zero regardless of its atomicity.
2
Calculate the oxidation state of sulfur in H2SO4H_2SO_4.
Oxidation state of sulfur in H2SO4=+6H_2SO_4 = +6.
Assign +1+1 for each hydrogen atom and 2-2 for each oxygen atom. Solving 2(+1)+S+4(2)=02(+1) + S + 4(-2) = 0 gives +2+S8=0+2 + S - 8 = 0, hence S=+6S = +6.

Anahtar Kavram

Assigning oxidation states to free elemental forms and central atoms in polyatomic oxoacids
Soru 3563Soru

For the interval 0x3600^\circ \le x \le 360^\circ, solve the trigonometric equation 2cos2xcosx1=02\cos^2 x - \cos x - 1 = 0. Which set contains all the solutions for xx?

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Cevap: 0,120,240,3600^\circ, 120^\circ, 240^\circ, 360^\circ

Cevap

The complete set of solutions is 0,120,240,3600^\circ, 120^\circ, 240^\circ, 360^\circ.
Factoring 2cos2xcosx1=02\cos^2 x - \cos x - 1 = 0 gives (2cosx+1)(cosx1)=0(2\cos x + 1)(\cos x - 1) = 0. Setting the first factor to zero yields cosx=12\cos x = -\frac{1}{2}, which has solutions at 120120^\circ and 240240^\circ in the interval [0,360][0^\circ, 360^\circ]. Setting the second factor to zero gives cosx=1\cos x = 1, which has solutions at 00^\circ and 360360^\circ. Combining these yields the set 0,120,240,3600^\circ, 120^\circ, 240^\circ, 360^\circ.

Adım Adım Çözüm

1
Factor the quadratic trigonometric equation
(2cosx+1)(cosx1)=0(2\cos x + 1)(\cos x - 1) = 0
Treat cosx\cos x as a single variable to simplify into standard quadratic factors.
2
Set each factor to zero to find values for cosx\cos x
cosx=1\cos x = 1 or cosx=12\cos x = -\frac{1}{2}
Zero-product property requires at least one factor to be zero.
3
Solve for xx in the interval 0x3600^\circ \le x \le 360^\circ
For cosx=1\cos x = 1: x=0,360x = 0^\circ, 360^\circ. For cosx=12\cos x = -\frac{1}{2}: x=18060=120x = 180^\circ - 60^\circ = 120^\circ (Quadrant II) and x=180+60=240x = 180^\circ + 60^\circ = 240^\circ (Quadrant III).
Cosine is negative in Quadrants II and III, with a reference angle of 6060^\circ.
4
Combine all unique solutions in ascending order
x=0,120,240,360x = 0^\circ, 120^\circ, 240^\circ, 360^\circ
Include all solutions within the given domain boundaries.

Anahtar Kavram

Solving Quadratic Trigonometric Equations
Soru 3564Soru

The aerodynamic drag force FF acting on an object moving through a fluid of density ρ\rho with cross-sectional area AA at speed vv is modeled by the equation F=12CdρaAbvcF = \frac{1}{2} C_d \rho^a A^b v^c, where CdC_d is a dimensionless constant. Using dimensional analysis, what is the numerical value of the exponent cc?

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Cevap: 2

Cevap

The numerical value of the exponent cc is 2.
By applying the principle of dimensional homogeneity, the base dimension of time on the left side is T2\text{T}^{-2} (from force [F]=M L T2[F] = \text{M L T}^{-2}). On the right side, the only quantity containing time is velocity [v]=L T1[v] = \text{L T}^{-1}, raised to power cc, giving Tc\text{T}^{-c}. Equating the exponents gives 2=c-2 = -c, so c=2c = 2.

Adım Adım Çözüm

1
Identify the base dimensions of each physical quantity in the given equation.
[F]=M L T2[F] = \text{M L T}^{-2}, [ρ]=M L3[\rho] = \text{M L}^{-3}, [A]=L2[A] = \text{L}^2, and [v]=L T1[v] = \text{L T}^{-1}. CdC_d is dimensionless ([Cd]=1[C_d] = 1).
Dimensional homogeneity requires both sides of a physical equation to have identical base dimensions.
2
Substitute the base dimensions into the formula F=12CdρaAbvcF = \frac{1}{2} C_d \rho^a A^b v^c and simplify.
\text{M L T}^{-2} = (\text{M L}^{-3})^a (\text{L}^2)^b (\text{L T}^{-1})^c = \text{M}^a \text{L}^{-3a + 2b + c} \text{T}^{-c}.
Combining powers of base dimensions allows direct comparison of corresponding exponents.
3
Equate the exponent of time (T) on both sides of the dimensional equation.
-2 = -c \implies c = 2.
The exponent of T on the left side is -2, which must equal the exponent of T on the right side (-c).

Anahtar Kavram

Principle of Dimensional Homogeneity
Tahmini Süre:1m 15s
Soru 3565Soru

An alternating current (AC) series circuit contains a resistor of resistance R=30 ΩR = 30\ \Omega, an inductor of inductive reactance XL=80 ΩX_L = 80\ \Omega, and a capacitor of capacitive reactance XC=40 ΩX_C = 40\ \Omega. The circuit is connected across an AC supply with a peak voltage of V0=1002 VV_0 = 100\sqrt{2}\text{ V}. What is the average power dissipated in the circuit?

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Cevap: 120 W120\text{ W}

Cevap

The average electrical power dissipated in the circuit is 120 W120\text{ W}.
The average power dissipated in an AC series circuit depends solely on the resistive component. First, converting peak voltage V0=1002 VV_0 = 100\sqrt{2}\text{ V} yields an RMS voltage of Vrms=100 VV_{\text{rms}} = 100\text{ V}. Computing the circuit impedance yields Z=302+(8040)2=50 ΩZ = \sqrt{30^2 + (80 - 40)^2} = 50\ \Omega. This produces an RMS current of Irms=10050=2 AI_{\text{rms}} = \frac{100}{50} = 2\text{ A}. Finally, substituting into Pavg=Irms2RP_{\text{avg}} = I_{\text{rms}}^2 R gives (2)2×30=120 W(2)^2 \times 30 = 120\text{ W}.

Adım Adım Çözüm

1
Calculate the root-mean-square (RMS) voltage of the AC supply.
Vrms=V02=10022=100 VV_{\text{rms}} = \frac{V_0}{\sqrt{2}} = \frac{100\sqrt{2}}{\sqrt{2}} = 100\text{ V}
AC power calculations require RMS voltage values rather than peak voltage values.
2
Calculate the net impedance (ZZ) of the series RLC circuit.
Z=R2+(XLXC)2=302+(8040)2=302+402=2500=50 ΩZ = \sqrt{R^2 + (X_L - X_C)^2} = \sqrt{30^2 + (80 - 40)^2} = \sqrt{30^2 + 40^2} = \sqrt{2500} = 50\ \Omega
Resistance and reactances combine quadratically due to phase differences between voltage across components.
3
Calculate the RMS current (IrmsI_{\text{rms}}) flowing through the circuit.
Irms=VrmsZ=100 V50 Ω=2 AI_{\text{rms}} = \frac{V_{\text{rms}}}{Z} = \frac{100\text{ V}}{50\ \Omega} = 2\text{ A}
Ohm's law for AC circuits states Irms=VrmsZI_{\text{rms}} = \frac{V_{\text{rms}}}{Z}.
4
Calculate the average power dissipated in the circuit.
Pavg=Irms2R=(2 A)2×30 Ω=120 WP_{\text{avg}} = I_{\text{rms}}^2 R = (2\text{ A})^2 \times 30\ \Omega = 120\text{ W}
Power is dissipated only in resistive elements, as pure inductors and capacitors store and return energy without net loss.

Anahtar Kavram

Impedance and Power in Series AC Circuits
Soru 3566Soru

In a resonance tube experiment using a tuning fork of constant frequency, the first two consecutive resonant lengths of the air column above the water level are measured to be 23.5 cm23.5\text{ cm} and 73.5 cm73.5\text{ cm} respectively. What is the end correction of the tube in centimeters?

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Cevap: 1.5

Cevap

The end correction of the tube is 1.5 cm1.5\text{ cm}.
In a resonance tube closed at one end by water, consecutive resonances occur when the air column length increases by half a wavelength. Subtracting the first resonant length from the second gives λ2=73.5 cm23.5 cm=50.0 cm\frac{\lambda}{2} = 73.5\text{ cm} - 23.5\text{ cm} = 50.0\text{ cm}, which yields λ=100.0 cm\lambda = 100.0\text{ cm} and λ4=25.0 cm\frac{\lambda}{4} = 25.0\text{ cm}. The first resonance condition accounts for end correction through L1+e=λ4L_1 + e = \frac{\lambda}{4}. Substituting L1=23.5 cmL_1 = 23.5\text{ cm} gives e=25.0 cm23.5 cm=1.5 cme = 25.0\text{ cm} - 23.5\text{ cm} = 1.5\text{ cm}.

Adım Adım Çözüm

1
Determine the wavelength using consecutive resonant positions
\(\frac{\lambda}{2} = L_2 - L_1 = 73.5\text{ cm} - 23.5\text{ cm} = 50.0\text{ cm}\), so \(\lambda = 100.0\text{ cm}\)
For a column closed at one end, consecutive resonances occur at intervals of half a wavelength.
2
Calculate the quarter-wavelength value
\(\frac{\lambda}{4} = \frac{100.0\text{ cm}}{4} = 25.0\text{ cm}\)
The fundamental mode position of the displacement antinode corresponds to a distance of one quarter-wavelength from the closed end.
3
Calculate the end correction
\(e = \frac{\lambda}{4} - L_1 = 25.0\text{ cm} - 23.5\text{ cm} = 1.5\text{ cm}\)
The effective length for the first resonance includes the physical length plus the end correction.

Anahtar Kavram

End Correction in Resonance Air Columns
Soru 3567Soru

Which of the following conditions is necessary for total internal reflection to occur when light travels between two media?

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Cevap: Light must travel from an optically denser medium to an optically less dense medium, and the angle of incidence must be greater than the critical angle.

Cevap

Total internal reflection requires light to travel from an optically denser medium to an optically less dense medium with an angle of incidence greater than the critical angle.
For total internal reflection to happen, two strict conditions must be satisfied: (1) light must travel from a medium with a higher refractive index to one with a lower refractive index, and (2) the angle of incidence must be strictly greater than the critical angle for that boundary.

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1
Identify the optical density requirement
Light must attempt to pass from a medium of higher refractive index (denser) into a medium of lower refractive index (less dense) so that the refracted ray bends away from the normal.
Bending away from the normal allows the angle of refraction to reach 9090^\circ at the critical angle.
2
Identify the angle of incidence requirement
The angle of incidence in the denser medium must exceed the critical angle (i>Ci > C).
When the incidence angle exceeds the critical angle, no refraction is possible and all energy is reflected back into the denser medium.

Anahtar Kavram

Conditions for Total Internal Reflection
Soru 3568Soru

The perimeter of a rectangular playfield is 28 m28\text{ m} and its area is 40 m240\text{ m}^2. What is the positive difference, in metres, between its length and width?

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Cevap: 6

Cevap

The positive difference between the length and width of the playfield is 6 metres.
Formulating the system gives x+y=14x + y = 14 and xy=40xy = 40. Substituting y=14xy = 14 - x yields the quadratic equation x214x+40=0x^2 - 14x + 40 = 0, which factors into (x10)(x4)=0(x - 10)(x - 4) = 0. The dimensions are 10 m10\text{ m} and 4 m4\text{ m}, giving a positive difference of 104=6 m10 - 4 = 6\text{ m}.

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1
Set up linear and quadratic equations for perimeter and area
x+y=14x + y = 14 and xy=40xy = 40
Perimeter formula is 2(x+y)=282(x + y) = 28 which simplifies to x+y=14x + y = 14, and area formula is xy=40xy = 40.
2
Substitute y=14xy = 14 - x into the quadratic area equation
x(14x)=40    x214x+40=0x(14 - x) = 40 \implies x^2 - 14x + 40 = 0
Substitution reduces the simultaneous system to a single quadratic equation in terms of xx.
3
Solve the quadratic equation by factoring
(x10)(x4)=0    x=10 or x=4(x - 10)(x - 4) = 0 \implies x = 10 \text{ or } x = 4
The roots of the equation give the dimensions of the rectangle.
4
Calculate the positive difference between the two dimensions
10 - 4 = 6
Subtract the smaller dimension from the larger dimension.

Anahtar Kavram

Solving word problems involving simultaneous linear and quadratic equations
Tahmini Süre:1m 30s
Soru 3569Soru

A quantity PP varies partially as xx and partially as the square of yy. When x=2x = 2 and y=3y = 3, P=24P = 24, and when x=5x = 5 and y=1y = 1, P=17P = 17. What is the value of PP when x=4x = 4 and y=3y = 3?

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Cevap: 30

Cevap

The value of PP is 30.
The relationship follows the partial variation formula P=k1x+k2y2P = k_1 x + k_2 y^2. Substituting the given conditions gives 2k1+9k2=242k_1 + 9k_2 = 24 and 5k1+k2=175k_1 + k_2 = 17. Solving these simultaneous equations yields k1=3k_1 = 3 and k2=2k_2 = 2. Evaluating P=3(4)+2(32)P = 3(4) + 2(3^2) produces 12+18=3012 + 18 = 30.

Adım Adım Çözüm

1
Set up the general formula for partial variation.
P=k1x+k2y2P = k_1 x + k_2 y^2, where k1k_1 and k2k_2 are constants.
Partial variation combines terms linearly with separate variation constants.
2
Substitute the given pairs of values to form simultaneous linear equations.
Equation (1): 2k1+9k2=242k_1 + 9k_2 = 24; Equation (2): 5k1+k2=175k_1 + k_2 = 17.
Plugging in (x=2,y=3,P=24)(x=2, y=3, P=24) and (x=5,y=1,P=17)(x=5, y=1, P=17) creates a system of equations in terms of k1k_1 and k2k_2.
3
Solve the simultaneous linear equations for k1k_1 and k2k_2.
From Equation (2), k2=175k1k_2 = 17 - 5k_1. Substitute into Equation (1): 2k1+9(175k1)=24    43k1=129    k1=32k_1 + 9(17 - 5k_1) = 24 \implies -43k_1 = -129 \implies k_1 = 3. Then k2=175(3)=2k_2 = 17 - 5(3) = 2.
Finding the specific values of the variation constants is required to complete the formula.
4
Calculate PP for x=4x = 4 and y=3y = 3 using the complete formula P=3x+2y2P = 3x + 2y^2.
P=3(4)+2(32)=12+2(9)=12+18=30P = 3(4) + 2(3^2) = 12 + 2(9) = 12 + 18 = 30.
Evaluating the relationship with the target parameters produces the final answer.

Anahtar Kavram

Partial Variation and Simultaneous Linear Equations
Tahmini Süre:2m 0s
Soru 3570Soru

Given the 3×33 \times 3 matrix A=(x213121x0)A = \begin{pmatrix} x & 2 & 1 \\ 3 & 1 & 2 \\ 1 & x & 0 \end{pmatrix}, find the positive value of xx for which det(A)=2\det(A) = -2.

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Cevap: 2.5

Cevap

The positive value of xx is 2.5.
Expanding the determinant of matrix AA along the third row gives 1(41)x(2x3)=2x2+3x+31(4 - 1) - x(2x - 3) = -2x^2 + 3x + 3. Setting this equal to 2-2 yields 2x23x5=02x^2 - 3x - 5 = 0. Factoring gives (2x5)(x+1)=0(2x - 5)(x + 1) = 0, yielding solutions x=2.5x = 2.5 and x=1x = -1. Taking the positive value gives x=2.5x = 2.5.

Adım Adım Çözüm

1
Calculate the determinant of matrix AA in terms of xx
det(A)=2x2+3x+3\det(A) = -2x^2 + 3x + 3
Expanding along the third row simplifies computation because of the zero entry.
2
Set the determinant expression equal to 2-2 and rearrange terms
2x23x5=02x^2 - 3x - 5 = 0
Setting 2x2+3x+3=2-2x^2 + 3x + 3 = -2 forms a standard quadratic equation.
3
Factorize the quadratic equation to find the roots
x=2.5x = 2.5 or x=1x = -1
Factoring (2x5)(x+1)=0(2x - 5)(x + 1) = 0 yields two real solutions.
4
Filter for the positive value requested in the stem
x=2.5x = 2.5
The question specifically requires the positive value of xx.

Anahtar Kavram

Determinant of a 3x3 Matrix and Quadratic Equation Solving
Tahmini Süre:2m 30s
Soru 3571Soru

If log3x2logx3=1\log_3 x - 2 \log_x 3 = 1, what is the sum of all valid solutions for xx?

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Cevap: 283\frac{28}{3}

Cevap

The sum of all valid solutions for xx is 283\frac{28}{3}.
By using the change of base identity logx3=1log3x\log_x 3 = \frac{1}{\log_3 x} and substituting u=log3xu = \log_3 x, the given equation simplifies to u2u=1u - \frac{2}{u} = 1. Multiplying by uu gives the quadratic equation u2u2=0u^2 - u - 2 = 0, which factors as (u2)(u+1)=0(u - 2)(u + 1) = 0. This yields u=2u = 2 or u=1u = -1. Converting back to xx gives x=32=9x = 3^2 = 9 and x=31=13x = 3^{-1} = \frac{1}{3}. Both values satisfy domain constraints for logarithmic base (x>0x > 0 and x1x \neq 1). Adding these values gives 9+13=2839 + \frac{1}{3} = \frac{28}{3}.

Adım Adım Çözüm

1
Apply the change of base formula to express the equation with a common logarithmic base
Using logx3=1log3x\log_x 3 = \frac{1}{\log_3 x}, the equation becomes log3x2log3x=1\log_3 x - \frac{2}{\log_3 x} = 1.
Change of base allows all terms containing xx to be represented in terms of a single logarithmic expression.
2
Substitute u=log3xu = \log_3 x and clear the fraction to form a quadratic equation
u2u=1    u2u2=0u - \frac{2}{u} = 1 \implies u^2 - u - 2 = 0.
Multiplying through by uu (where u0u \neq 0) transforms the logarithmic relationship into a standard quadratic algebraic equation.
3
Factor the quadratic equation to find the values of uu
(u2)(u+1)=0    u=2 or u=1(u - 2)(u + 1) = 0 \implies u = 2 \text{ or } u = -1.
Factoring isolates the linear roots for the substituted variable uu.
4
Solve for xx from u=log3xu = \log_3 x and verify validity within the domain
For u=2u = 2: log3x=2    x=32=9\log_3 x = 2 \implies x = 3^2 = 9.
For u=1u = -1: log3x=1    x=31=13\log_3 x = -1 \implies x = 3^{-1} = \frac{1}{3}.
Both solutions are positive and x1x \neq 1, so both are valid.
Converting from logarithmic form to exponential form retrieves the original variable xx.
5
Calculate the sum of all valid solutions
Sum = 9+13=273+13=2839 + \frac{1}{3} = \frac{27}{3} + \frac{1}{3} = \frac{28}{3}.
The question requires finding the total sum of all permissible real solutions for xx.

Anahtar Kavram

Logarithmic Change of Base and Equations Reducible to Quadratics
Soru 3572Soru

The table below shows the distribution of quiz scores for a class of students:

Score IntervalFrequency (ff)
151 - 533
6106 - 1055
111511 - 1577
162016 - 2055

Calculate the mean score of the distribution.

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Cevap: 11.5

Cevap

The mean score of the distribution is 11.5.
The mean for a grouped frequency table is calculated by taking the sum of the products of each midpoint (xx) and its frequency (ff), divided by the sum of all frequencies (ff). Here, fx=230\sum fx = 230 and f=20\sum f = 20, yielding xˉ=11.5\bar{x} = 11.5.

Adım Adım Çözüm

1
Determine the class midpoints (xx) for each interval.
Midpoints are 3, 8, 13, and 18.
Midpoints serve as the representative values for each class interval.
2
Calculate the product of each midpoint and frequency (fxfx).
Products are 9, 40, 91, and 90.
To find the total contribution of each class interval.
3
Find the sum of all frequencies (f\sum f) and products (fx\sum fx).
f=20\sum f = 20 and fx=230\sum fx = 230.
These totals are required for the grouped mean formula.
4
Divide the total product sum by total frequency.
xˉ=23020=11.5\bar{x} = \frac{230}{20} = 11.5.
Applying the formula for the mean of grouped data xˉ=fxf\bar{x} = \frac{\sum fx}{\sum f}.

Anahtar Kavram

Mean of Grouped Data using Class Midpoints
Soru 3573Soru

Find the smallest non-negative integer xx that satisfies the linear modular congruence 3x8(mod11)3x \equiv 8 \pmod{11}.

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Cevap: 10

Cevap

The smallest non-negative integer xx is 10.
Evaluating 3x8(mod11)3x \equiv 8 \pmod{11} by testing multiples of 1111 added to 88 gives 3030, which divided by 33 yields x=10x = 10. Since 10[0,10]10 \in [0, 10], it is the canonical solution.

Adım Adım Çözüm

1
Convert the modular congruence into an algebraic equation
3x=8+11k3x = 8 + 11k for an integer kk
By definition of congruence modulo 1111, 3x83x - 8 must be a multiple of 1111.
2
Find the smallest integer k0k \ge 0 such that 8+11k8 + 11k is divisible by 3
When k=2k = 2, 8+11(2)=308 + 11(2) = 30
3030 is divisible by 33 (30/3=1030 / 3 = 10).
3
Divide by 3 to isolate xx
x=10x = 10
3(10)=308(mod11)3(10) = 30 \equiv 8 \pmod{11}.

Anahtar Kavram

Linear Modular Congruence
Tahmini Süre:1m 15s
Soru 3574Soru

Find the real value of xx that satisfies the exponential equation 4x3x12=3x+1222x14^x - 3^{x - \frac{1}{2}} = 3^{x + \frac{1}{2}} - 2^{2x - 1}.

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Cevap: 1.5

Cevap

The value of xx is 1.51.5 (or 32\frac{3}{2}).
By using index laws to group base-2 terms on the left side and base-3 terms on the right side, we obtain 22x(32)=3x(43)2^{2x}\left(\frac{3}{2}\right) = 3^x\left(\frac{4}{\sqrt{3}}\right). Rearranging gives (43)x=833=(43)32\left(\frac{4}{3}\right)^x = \frac{8}{3\sqrt{3}} = \left(\frac{4}{3}\right)^{\frac{3}{2}}. Equating indices gives x=1.5x = 1.5.

Adım Adım Çözüm

1
Group like exponential terms with base 2 and base 3 on opposite sides of the equation.
4x+22x1=3x+12+3x124^x + 2^{2x - 1} = 3^{x + \frac{1}{2}} + 3^{x - \frac{1}{2}}
Grouping terms with common prime bases allows for factoring exponential terms.
2
Apply the product and power laws of indices: 4x=22x4^x = 2^{2x}, 22x1=2122x2^{2x-1} = 2^{-1} \cdot 2^{2x}, 3x±12=3x3±123^{x \pm \frac{1}{2}} = 3^x \cdot 3^{\pm \frac{1}{2}}.
22x+1222x=3x3+3x132^{2x} + \frac{1}{2} \cdot 2^{2x} = 3^x \cdot \sqrt{3} + 3^x \cdot \frac{1}{\sqrt{3}}
Separating the variable exponents from constant exponents prepares each side for factoring.
3
Factor out 22x2^{2x} from the left side and 3x3^x from the right side, then simplify arithmetic terms.
22x(32)=3x(43)2^{2x}\left(\frac{3}{2}\right) = 3^x\left(\frac{4}{\sqrt{3}}\right)
Factoring isolates the variable terms 22x2^{2x} and 3x3^x from numerical constants.
4
Divide to form the ratio 4x3x=(43)x\frac{4^x}{3^x} = \left(\frac{4}{3}\right)^x and simplify the numerical fraction on the right.
(43)x=833\left(\frac{4}{3}\right)^x = \frac{8}{3\sqrt{3}}
Expressing both sides with unified variable bases facilitates solving for xx by equating powers.
5
Rewrite 833\frac{8}{3\sqrt{3}} as a power of 43\frac{4}{3} and solve for xx.
(43)x=(43)32    x=32=1.5\left(\frac{4}{3}\right)^x = \left(\frac{4}{3}\right)^{\frac{3}{2}} \implies x = \frac{3}{2} = 1.5
Since 833=43/233/2=(43)3/2\frac{8}{3\sqrt{3}} = \frac{4^{3/2}}{3^{3/2}} = (\frac{4}{3})^{3/2}, equating exponents yields x=1.5x = 1.5.

Anahtar Kavram

Solving mixed-base exponential equations by grouping, factoring, and converting to a unified base ratio.
Tahmini Süre:3m 0s
Soru 3575Soru

Match each vocabulary word in the left column with its precise antonym (word opposite in meaning) in the right column.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Diligent
Humble
Friendly
Permanent

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Diligent pairs with Lazy; Humble pairs with Arrogant; Friendly pairs with Hostile; Permanent pairs with Temporary.
Each word on the left is matched with its exact antonym on the right: Diligent (hardworking) is opposite to Lazy; Humble (modest) is opposite to Arrogant; Friendly (kind) is opposite to Hostile; Permanent (lasting) is opposite to Temporary.

Adım Adım Çözüm

1
Define each target word in the left column.
Diligent means hardworking; Humble means modest; Friendly means pleasant/kind; Permanent means lasting indefinitely.
Establishing clear definitions is necessary to determine precise antonyms.
2
Find the corresponding word in the right column that expresses the direct opposite meaning.
Diligent matches Lazy; Humble matches Arrogant; Friendly matches Hostile; Permanent matches Temporary.
Antonyms express contrasting or opposing semantic qualities.

Anahtar Kavram

Antonyms and Words Opposite in Meaning
Soru 3576Soru

Solve the simultaneous equations y=2x+1y = 2x + 1 and y=x22y = x^2 - 2. Which of the following represents the complete set of solution pairs (x,y)(x, y)?

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Cevap: (3,7)(3, 7) and (1,1)(-1, -1)

Cevap

The complete set of solution pairs (x,y)(x, y) is (3,7)(3, 7) and (1,1)(-1, -1).
Equating 2x+1=x222x + 1 = x^2 - 2 yields x22x3=0x^2 - 2x - 3 = 0. Factoring gives (x3)(x+1)=0(x - 3)(x + 1) = 0, leading to x=3x = 3 or x=1x = -1. Substituting these xx-values into y=2x+1y = 2x + 1 gives y=7y = 7 for x=3x = 3, and y=1y = -1 for x=1x = -1. Thus, the solution pairs are (3,7)(3, 7) and (1,1)(-1, -1).

Adım Adım Çözüm

1
Equate the linear expression for yy to the quadratic expression for yy.
2x+1=x222x + 1 = x^2 - 2
Since both expressions equal yy, setting them equal eliminates yy.
2
Rearrange the equation into standard quadratic form ax2+bx+c=0ax^2 + bx + c = 0.
x22x3=0x^2 - 2x - 3 = 0
Subtract 2x2x and 11 from both sides.
3
Factor the quadratic equation to find the values of xx.
(x3)(x+1)=0    x=3 or x=1(x - 3)(x + 1) = 0 \implies x = 3 \text{ or } x = -1
Determine two numbers that multiply to 3-3 and add to 2-2.
4
Substitute each xx-value back into the linear equation y=2x+1y = 2x + 1 to find the corresponding yy-value.
For x=3x = 3, y=2(3)+1=7y = 2(3) + 1 = 7. For x=1x = -1, y=2(1)+1=1y = 2(-1) + 1 = -1.
Calculate the exact coordinate pairs (x,y)(x, y) that satisfy both equations.

Anahtar Kavram

Solving simultaneous linear and quadratic equations using algebraic substitution.
Soru 3577Soru

A particle starts from rest and accelerates uniformly at a rate of 4 m/s24\text{ m/s}^2 for a duration t1t_1. Immediately after reaching its maximum velocity, it decelerates uniformly at 2 m/s22\text{ m/s}^2 until coming to rest. If the total distance covered during the entire motion is 600 m600\text{ m}, what is the total time of motion in seconds?

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Cevap: 30

Cevap

The total time of motion is 30 seconds.
For a two-stage motion starting and ending at rest, the peak velocity is vmax=a1t1=a2t2v_{\text{max}} = a_1 t_1 = a_2 t_2, giving a time ratio t2/t1=a1/a2=4/2=2t_2 / t_1 = a_1 / a_2 = 4 / 2 = 2. The total distance SS is the area under the velocity-time triangle, S=12vmax(t1+t2)=12(4t1)(3t1)=6t12S = \frac{1}{2} v_{\text{max}} (t_1 + t_2) = \frac{1}{2} (4 t_1) (3 t_1) = 6 t_1^2. Setting 6t12=6006 t_1^2 = 600 yields t1=10 st_1 = 10\text{ s}, which gives a total time T=t1+t2=30 sT = t_1 + t_2 = 30\text{ s}.

Adım Adım Çözüm

1
Relate maximum velocity to the acceleration time t1t_1
vmax=4t1v_{\text{max}} = 4 t_1
Using v=u+atv = u + a t starting from rest (u=0u = 0).
2
Relate deceleration time t2t_2 to t1t_1
t2=2t1t_2 = 2 t_1
The final velocity is 00, so 0=vmaxa2t2    t2=4t12=2t10 = v_{\text{max}} - a_2 t_2 \implies t_2 = \frac{4 t_1}{2} = 2 t_1.
3
Express the total displacement SS as a function of t1t_1
S=6t12S = 6 t_1^2
Displacement during acceleration s1=12(4)t12=2t12s_1 = \frac{1}{2}(4)t_1^2 = 2 t_1^2. Displacement during deceleration s2=12(2)(2t1)2=4t12s_2 = \frac{1}{2}(2)(2 t_1)^2 = 4 t_1^2. Total S=2t12+4t12=6t12S = 2 t_1^2 + 4 t_1^2 = 6 t_1^2.
4
Solve for the acceleration time t1t_1
t1=10 st_1 = 10\text{ s}
Given S=600 mS = 600\text{ m}, we have 6t12=600    t12=100    t1=10 s6 t_1^2 = 600 \implies t_1^2 = 100 \implies t_1 = 10\text{ s}.
5
Calculate the total time of motion TT
T=30 sT = 30\text{ s}
Total time is the sum of both phases: T=t1+t2=t1+2t1=3t1=3(10)=30 sT = t_1 + t_2 = t_1 + 2 t_1 = 3 t_1 = 3(10) = 30\text{ s}.

Anahtar Kavram

Multi-stage uniform motion and average velocity relations
Tahmini Süre:3m 0s
Soru 3578Soru

A curve is defined by the equation y=x25x+6y = x^2 - 5x + 6. What is the xx-intercept of the line normal to the curve at the point where x=1x = 1?

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Cevap: -5

Cevap

The x-intercept of the normal line to the curve at x = 1 is -5.
Substituting x=1x = 1 into y=x25x+6y = x^2 - 5x + 6 yields y=2y = 2, identifying the point (1,2)(1, 2). Differentiating gives dydx=2x5\frac{dy}{dx} = 2x - 5, which equals 3-3 at x=1x = 1. The normal line gradient is the negative reciprocal, 13\frac{1}{3}. The line equation y2=13(x1)y - 2 = \frac{1}{3}(x - 1) simplifies to x3y+5=0x - 3y + 5 = 0. Setting y=0y = 0 gives x=5x = -5.

Adım Adım Çözüm

1
Calculate the y-coordinate at x = 1 to determine the point of tangency
Substituting x=1x = 1 into y=x25x+6y = x^2 - 5x + 6 gives y=(1)25(1)+6=2y = (1)^2 - 5(1) + 6 = 2, yielding the point (1,2)(1, 2).
The normal line intersects the curve at the point of tangency.
2
Find the derivative of the curve and evaluate the tangent slope
dydx=2x5\frac{dy}{dx} = 2x - 5. At x=1x = 1, mt=2(1)5=3m_t = 2(1) - 5 = -3.
The derivative evaluated at a specific point gives the slope of the tangent line to the curve.
3
Compute the slope of the normal line
mn=1mt=13=13m_n = -\frac{1}{m_t} = -\frac{1}{-3} = \frac{1}{3}.
The normal line is perpendicular to the tangent line, so its gradient is the negative reciprocal of the tangent gradient.
4
Construct the normal line equation and determine its x-intercept
Using point-slope form: y2=13(x1)    3y6=x1    x3y+5=0y - 2 = \frac{1}{3}(x - 1) \implies 3y - 6 = x - 1 \implies x - 3y + 5 = 0. Setting y=0y = 0 gives x+5=0    x=5x + 5 = 0 \implies x = -5.
The xx-intercept occurs where the line crosses the xx-axis, meaning y=0y = 0.

Anahtar Kavram

The slope of the normal line to a curve y=f(x)y = f(x) at x=ax = a is the negative reciprocal of the derivative at that point, mn=1f(a)m_n = -\frac{1}{f'(a)}.
Soru 3579Soru

If the matrix P=(k3121k420)P = \begin{pmatrix} k & 3 & 1 \\ 2 & 1 & k \\ 4 & 2 & 0 \end{pmatrix} is singular, find the non-zero value of kk.

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Cevap: 6

Cevap

The non-zero value of kk is 6.
For matrix P to be singular, its determinant must be 0. Expanding along row 3 yields 4(3k - 1) - 2(k^2 - 2) = 12k - 4 - 2k^2 + 4 = -2k^2 + 12k = 0. Factoring gives -2k(k - 6) = 0, which yields k = 0 or k = 6. The non-zero value is 6.

Adım Adım Çözüm

1
Set the determinant of matrix P to 0
\det(P) = 0
A matrix is singular if and only if its determinant equals zero.
2
Evaluate the 3x3 determinant by expanding along the third row
4 \cdot (3k - 1) - 2 \cdot (k^2 - 2) + 0 = 0
Expanding along the third row takes advantage of the zero entry to simplify computation.
3
Expand and combine like terms
-2k^2 + 12k = 0
12k - 4 - 2k^2 + 4 reduces to -2k^2 + 12k.
4
Factor out common factors and solve for k
-2k(k - 6) = 0 \implies k = 0 \text{ or } k = 6
Applying the zero-product property.
5
Select the required root
k = 6
The question specifies the non-zero value of k.

Anahtar Kavram

Determinant of a 3x3 matrix and singular matrix condition
Tahmini Süre:2m 0s
Soru 3580Soru

A body of mass 0.4 kg0.4\text{ kg} suspended vertically from a helical spring produces a static extension of 0.1 m0.1\text{ m}. The body is then pulled down further and set into vertical simple harmonic motion with an amplitude of 0.05 m0.05\text{ m}. What is the maximum velocity of the body in m/s\text{m/s}? (Take g=10 m/s2g = 10\text{ m/s}^2)

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Cevap: 0.5

Cevap

The maximum velocity of the body during oscillation is 0.5 m/s0.5\text{ m/s}.
At static equilibrium, weight balances restoring force (mg=kemg = ke), giving km=ge=100.1=100 s2\frac{k}{m} = \frac{g}{e} = \frac{10}{0.1} = 100\text{ s}^{-2}. The angular frequency is ω=km=10 rad/s\omega = \sqrt{\frac{k}{m}} = 10\text{ rad/s}. In SHM, the maximum velocity occurs at the central equilibrium position and is given by vmax=ωA=10×0.05=0.5 m/sv_{\max} = \omega A = 10 \times 0.05 = 0.5\text{ m/s}.

Adım Adım Çözüm

1
Relate spring stiffness to static extension
km=100 s2\frac{k}{m} = 100\text{ s}^{-2}
At vertical static equilibrium, the weight of the mass equals the restoring force: mg=ke    km=ge=10 m/s20.1 m=100 s2mg = ke \implies \frac{k}{m} = \frac{g}{e} = \frac{10\text{ m/s}^2}{0.1\text{ m}} = 100\text{ s}^{-2}.
2
Determine the angular frequency
ω=10 rad/s\omega = 10\text{ rad/s}
The angular frequency of a mass-spring system is given by ω=km=100=10 rad/s\omega = \sqrt{\frac{k}{m}} = \sqrt{100} = 10\text{ rad/s}.
3
Calculate maximum velocity
v_{\max} = 0.5\text{ m/s}
The maximum speed in simple harmonic motion occurs at the equilibrium position and is computed using vmax=ωA=10 rad/s×0.05 m=0.5 m/sv_{\max} = \omega A = 10\text{ rad/s} \times 0.05\text{ m} = 0.5\text{ m/s}.

Anahtar Kavram

Maximum velocity and angular frequency derived from static extension in Simple Harmonic Motion
ÖncekiSayfa 179 / 697Sonraki
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