Geometry and Trigonometry

178 soru

Soru 21Soru

A sphere has a surface area of 144π144\pi square inches. What is the volume, in cubic inches, of the sphere?

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Cevap: 288π288\pi

Cevap

The volume of the sphere is 288π288\pi cubic inches.
The surface area of a sphere is given by A=4πr2A = 4\pi r^2, where rr is the radius. Setting this equal to the given surface area yields 4πr2=144π4\pi r^2 = 144\pi, which simplifies to r2=36r^2 = 36, meaning the radius of the sphere is 66 inches. The volume of a sphere is given by V=43πr3V = \frac{4}{3}\pi r^3. Substituting r=6r = 6 into this formula gives V=43π(63)=43π(216)=288πV = \frac{4}{3}\pi (6^3) = \frac{4}{3}\pi (216) = 288\pi cubic inches.

Adım Adım Çözüm

1
Set the formula for the surface area of a sphere, A=4πr2A = 4\pi r^2, equal to the given surface area of 144π144\pi.
4πr2=144π4\pi r^2 = 144\pi, which simplifies to r2=36r^2 = 36.
To find the square of the radius of the sphere.
2
Take the square root of both sides to find the radius rr.
r=6r = 6.
The radius of a sphere must be a positive number.
3
Substitute the radius r=6r = 6 into the formula for the volume of a sphere, V=43πr3V = \frac{4}{3}\pi r^3.
V=43π(63)=43π(216)=288πV = \frac{4}{3}\pi(6^3) = \frac{4}{3}\pi(216) = 288\pi.
To compute the final volume of the sphere.

Anahtar Kavram

The volume of a sphere can be calculated by first finding its radius from its surface area using the formulas A=4πr2A = 4\pi r^2 and V=43πr3V = \frac{4}{3}\pi r^3.
Soru 22Soru

A solid sphere has a volume of 36π36\pi cubic centimeters. What is the radius, in centimeters, of the sphere?

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Cevap: 3

Cevap

The radius of the sphere is 3 centimeters.
The volume of a sphere is given by the formula V=43πr3V = \frac{4}{3}\pi r^3. Substituting 36π36\pi for VV gives 36π=43πr336\pi = \frac{4}{3}\pi r^3. Dividing both sides by π\pi results in 36=43r336 = \frac{4}{3}r^3. Multiplying both sides by 34\frac{3}{4} yields 27=r327 = r^3. Taking the cube root of both sides gives r=3r = 3. Thus, the radius of the sphere is 3 centimeters.

Adım Adım Çözüm

1
State the sphere volume formula.
V=43πr3V = \frac{4}{3}\pi r^3
The volume of a sphere is calculated using this standard formula relating volume to radius.
2
Substitute the given volume value into the formula.
36π=43πr336\pi = \frac{4}{3}\pi r^3
The problem specifies the volume is 36π36\pi cubic centimeters.
3
Solve for the radius cubed (r3r^3).
r3=27r^3 = 27
Dividing both sides of the equation by π\pi yields 36=43r336 = \frac{4}{3}r^3, and multiplying both sides by 34\frac{3}{4} isolates r3r^3 to give 27.
4
Take the cube root of both sides to find the radius (rr).
r=3r = 3
The cube root of 27 is 3, since 3×3×3=273 \times 3 \times 3 = 27.

Anahtar Kavram

Using the volume of a sphere formula to solve for an unknown radius.
Soru 23Soru

A right circular cylindrical tank with a base radius of 4 inches4\text{ inches} contains water. A solid metal sphere with a radius of 3 inches3\text{ inches} is completely submerged in the water, causing the water level to rise. If no water overflows from the tank, what is the increase, in inches, in the water level of the tank?

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Cevap: 2.25

Cevap

2.25
The correct answer is 2.25. The volume of the submerged sphere is calculated using the formula V=43πr3V = \frac{4}{3}\pi r^3. With a radius of 3 inches3\text{ inches}, the volume is V=43π(3)3=36π cubic inchesV = \frac{4}{3}\pi (3)^3 = 36\pi\text{ cubic inches}. The volume of the displaced water is represented by a cylinder of radius 4 inches4\text{ inches} and height hh, which represents the increase in water level. The volume of this displaced cylinder is V=π(4)2h=16πhV = \pi (4)^2 h = 16\pi h. Since the volume of the displaced water is equal to the volume of the submerged sphere, we set them equal: 16πh=36π16\pi h = 36\pi. Dividing both sides by 16π16\pi yields h=2.25h = 2.25.

Adım Adım Çözüm

1
Calculate the volume of the solid metal sphere using the formula V=43πr3V = \frac{4}{3}\pi r^3 with radius r=3 inchesr = 3\text{ inches}.
Vsphere=43π(3)3=36π cubic inchesV_{\text{sphere}} = \frac{4}{3}\pi (3)^3 = 36\pi\text{ cubic inches}
The volume of the sphere represents the total volume of water that will be displaced when the sphere is completely submerged.
2
Express the volume of the displaced water in the cylinder as a function of the rise in water level, hh.
Vdisplaced=π(4)2h=16πh cubic inchesV_{\text{displaced}} = \pi (4)^2 h = 16\pi h\text{ cubic inches}
The displaced water forms a cylindrical shape with the same base radius as the tank (4 inches4\text{ inches}) and a height equal to the change in the water level (hh).
3
Equate the volume of the displaced water to the volume of the sphere and solve for hh.
16πh=36πh=3616=2.25 inches16\pi h = 36\pi \Rightarrow h = \frac{36}{16} = 2.25\text{ inches}
By Archimedes' principle, the volume of the displaced water must equal the volume of the fully submerged solid sphere.

Anahtar Kavram

Equating the volume of a submerged object to the volume of displaced liquid in a cylindrical container.
Tahmini Süre:2m 0s
Soru 24Soru

A right square pyramid has a height of 9 centimeters9\text{ centimeters} and a square base with a side length of 5 centimeters5\text{ centimeters}. What is the volume, in cubic centimeters, of the pyramid?

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Cevap: 75

Cevap

75
The volume of a right square pyramid is given by the formula V=13BhV = \frac{1}{3}Bh, where BB is the area of the base and hh is the height. Since the base is a square with side length 5 centimeters5\text{ centimeters}, its area is B=52=25 square centimetersB = 5^2 = 25\text{ square centimeters}. Substituting the base area and the height of 9 centimeters9\text{ centimeters} into the formula gives V=13×25×9=75 cubic centimetersV = \frac{1}{3} \times 25 \times 9 = 75\text{ cubic centimeters}.

Adım Adım Çözüm

1
Calculate the area of the square base (BB).
B=52=25 square centimetersB = 5^2 = 25\text{ square centimeters}
The base is a square with side length 5 centimeters5\text{ centimeters}, and the area of a square is calculated by squaring its side length.
2
Apply the volume formula for a pyramid: V=13BhV = \frac{1}{3}Bh.
V=13×25×9=75 cubic centimetersV = \frac{1}{3} \times 25 \times 9 = 75\text{ cubic centimeters}
Substituting the base area of 25 square centimeters25\text{ square centimeters} and the height of 9 centimeters9\text{ centimeters} into the pyramid volume formula yields the volume.

Anahtar Kavram

The volume of a pyramid is calculated using the formula V=13BhV = \frac{1}{3}Bh, where BB is the area of the base and hh is the height.
Tahmini Süre:45s
Soru 25Soru

A solid metal right circular cylinder has a height of hh and a base radius of rr, where h>2rh > 2r. From one flat end of the cylinder, a hemisphere of radius rr is carved out. From the other flat end, a right circular cone of base radius rr and height h2rh - 2r is carved out. If the volume of the remaining solid is equal to the volume of a sphere with radius RR, which of the following equations represents RR in terms of rr and hh?

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Cevap: R=r2h23R = \sqrt[3]{\frac{r^2 h}{2}}

Cevap

The correct equation is R=r2h23R = \sqrt[3]{\frac{r^2 h}{2}}
The volume of the cylinder is πr2h\pi r^2 h. Subtracting the hemisphere's volume (23πr3\frac{2}{3}\pi r^3) and the cone's volume (13πr2(h2r)=13πr2h23πr3\frac{1}{3}\pi r^2(h - 2r) = \frac{1}{3}\pi r^2 h - \frac{2}{3}\pi r^3) leaves a remaining volume of 23πr2h\frac{2}{3}\pi r^2 h. Setting this equal to the volume of a sphere of radius RR (43πR3\frac{4}{3}\pi R^3) gives 43πR3=23πr2h\frac{4}{3}\pi R^3 = \frac{2}{3}\pi r^2 h. Simplifying this equation yields R3=r2h2R^3 = \frac{r^2 h}{2}, and taking the cube root gives the correct relation.

Adım Adım Çözüm

1
Write the formula for the volume of the original cylinder.
Vcylinder=πr2hV_{\text{cylinder}} = \pi r^2 h
The volume of a cylinder with radius rr and height hh is given by the formula πr2h\pi r^2 h.
2
Write the volume formulas for the carved-out shapes.
Vhemisphere=23πr3V_{\text{hemisphere}} = \frac{2}{3}\pi r^3 and Vcone=13πr2(h2r)V_{\text{cone}} = \frac{1}{3}\pi r^2 (h - 2r)
A hemisphere is half a sphere, so its volume is 23πr3\frac{2}{3}\pi r^3. The volume of a cone with radius rr and height h2rh - 2r is 13πr2(h2r)\frac{1}{3}\pi r^2 (h - 2r).
3
Subtract the volumes of the carved-out shapes from the cylinder's volume.
Vremaining=πr2h23πr313πr2(h2r)=23πr2hV_{\text{remaining}} = \pi r^2 h - \frac{2}{3}\pi r^3 - \frac{1}{3}\pi r^2 (h - 2r) = \frac{2}{3}\pi r^2 h
Expanding the cone's volume gives 13πr2h23πr3\frac{1}{3}\pi r^2 h - \frac{2}{3}\pi r^3. Subtracting this and the hemisphere's volume from the cylinder's volume simplifies to 23πr2h\frac{2}{3}\pi r^2 h because the πr3\pi r^3 terms cancel out.
4
Equate the remaining volume to the volume of a sphere with radius RR and solve for RR.
43πR3=23πr2h    R3=r2h2    R=r2h23\frac{4}{3}\pi R^3 = \frac{2}{3}\pi r^2 h \implies R^3 = \frac{r^2 h}{2} \implies R = \sqrt[3]{\frac{r^2 h}{2}}
Equating the remaining volume to the volume of a sphere of radius RR and dividing both sides by 23π\frac{2}{3}\pi gives 2R3=r2h2 R^3 = r^2 h. Dividing by 2 and taking the cube root isolates RR.

Anahtar Kavram

Calculating and comparing volumes of combined geometric solids and algebraically isolating variables.
Tahmini Süre:3m 0s
Soru 26Soru

Right circular Cylinder AA has a base radius of rr and a height of hh. Right circular Cylinder BB has a base radius that is 33 times the base radius of Cylinder AA, and a height that is 12\frac{1}{2} the height of Cylinder AA. What is the ratio of the volume of Cylinder BB to the volume of Cylinder AA?

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Cevap: 92\frac{9}{2}

Cevap

The ratio of the volume of Cylinder BB to the volume of Cylinder AA is 92\frac{9}{2}.
The volume of a cylinder is given by the formula V=πr2hV = \pi r^2 h. For Cylinder AA, the volume is VA=πr2hV_A = \pi r^2 h. For Cylinder BB, the radius is 3r3r and the height is 12h\frac{1}{2}h. Substituting these values gives VB=π(3r)2(12h)=92πr2hV_B = \pi (3r)^2 \left(\frac{1}{2}h\right) = \frac{9}{2}\pi r^2 h. The ratio of the volume of Cylinder BB to the volume of Cylinder AA is therefore the ratio of nine to two.

Adım Adım Çözüm

1
Write the volume formula for Cylinder AA in terms of its radius rr and height hh.
VA=πr2hV_A = \pi r^2 h
To establish a baseline volume for Cylinder AA using the standard formula for the volume of a right circular cylinder.
2
Express the radius and height of Cylinder BB in terms of rr and hh, and substitute them into the volume formula.
The radius of Cylinder BB is 3r3r and the height is 12h\frac{1}{2}h. Thus, VB=π(3r)2(12h)=π(9r2)(12h)=92πr2hV_B = \pi (3r)^2 \left(\frac{1}{2}h\right) = \pi (9r^2) \left(\frac{1}{2}h\right) = \frac{9}{2}\pi r^2 h.
To find the volume of Cylinder BB expressed in terms of the variables rr and hh.
3
Divide the volume of Cylinder BB by the volume of Cylinder AA to find the ratio.
VBVA=92πr2hπr2h=92\frac{V_B}{V_A} = \frac{\frac{9}{2}\pi r^2 h}{\pi r^2 h} = \frac{9}{2}
To calculate the ratio of the volume of Cylinder BB to Cylinder AA.

Anahtar Kavram

Dimensional scaling of the volume of a cylinder
Soru 27Soru

A square picture has an area of 1616 square inches. If the side length of the picture is doubled, what is the area, in square inches, of the new picture?

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Cevap: 6464

Cevap

6464 square inches
The area of a square with side length ss is given by s2s^2. Since the original area is 1616 square inches, the original side length is 16=4\sqrt{16} = 4 inches. Doubling this side length gives a new side length of 88 inches. Therefore, the area of the new square is 82=648^2 = 64 square inches. Alternatively, when all linear dimensions of a two-dimensional shape are multiplied by a scale factor kk, the area is multiplied by k2k^2. Since the side length is doubled (k=2k = 2), the area is multiplied by 22=42^2 = 4, resulting in 16×4=6416 \times 4 = 64 square inches.

Adım Adım Çözüm

1
Determine the side length of the original square.
The side length is 16=4\sqrt{16} = 4 inches.
The area of a square is given by A=s2A = s^2, where ss is the side length. So, s=As = \sqrt{A}.
2
Calculate the side length of the new square after doubling.
The new side length is 4×2=84 \times 2 = 8 inches.
The problem states that the side length is doubled.
3
Calculate the area of the new square.
The new area is 82=648^2 = 64 square inches.
The area of the new square is the square of its new side length (8 inches×8 inches8 \text{ inches} \times 8 \text{ inches}).

Anahtar Kavram

When a two-dimensional shape is scaled by a factor of kk, its area is scaled by a factor of k2k^2.
Soru 28Soru

A solid rectangular prism has a volume of 192192 cubic inches. The ratio of the length of the prism to its width is 3:13:1, and the height of the prism is 44 inches. What is the surface area, in square inches, of the prism?

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Cevap: 224

Cevap

The surface area of the prism is 224 square inches.
The correct answer is 224. By using the volume formula V=lwhV = lwh with a volume of 192192 and a height of 44, the product of the length and width of the base is lw=48lw = 48. Given that the ratio of the length to the width is 3:13:1, the length can be written as l=3wl = 3w. Substituting this expression into the product equation gives 3w(w)=483w(w) = 48, or 3w2=483w^2 = 48. Dividing both sides by 3 yields w2=16w^2 = 16, which means the width of the prism is 44 inches. Since l=3wl = 3w, the length is 1212 inches. The surface area of the prism can be found using the formula SA=2(lw+lh+wh)SA = 2(lw + lh + wh). Substituting the dimensions l=12l = 12, w=4w = 4, and h=4h = 4 yields SA=2(124+124+44)=2(48+48+16)=2(112)=224SA = 2(12 \cdot 4 + 12 \cdot 4 + 4 \cdot 4) = 2(48 + 48 + 16) = 2(112) = 224 square inches.

Adım Adım Çözüm

1
Use the volume formula for a rectangular prism, V=lwhV = lwh, and substitute the given volume of 192192 and height of 44.
192=lw4192 = l \cdot w \cdot 4, which simplifies to lw=48l \cdot w = 48.
To find the product of the length and width of the base of the prism.
2
Express the length in terms of the width using the ratio of 3:13:1.
l=3wl = 3w.
The ratio of the length to the width is given as 3 to 1.
3
Substitute l=3wl = 3w into the equation lw=48l \cdot w = 48 and solve for ww.
3ww=48    3w2=48    w2=16    w=43w \cdot w = 48 \implies 3w^2 = 48 \implies w^2 = 16 \implies w = 4.
To solve for the width of the rectangular prism.
4
Find the length of the rectangular prism.
l=3(4)=12l = 3(4) = 12 inches.
Since the length is 3 times the width and the width is 4 inches, the length must be 12 inches.
5
Use the surface area formula SA=2(lw+lh+wh)SA = 2(lw + lh + wh) with the dimensions l=12l = 12, w=4w = 4, and h=4h = 4.
SA=2(124+124+44)=2(48+48+16)=2(112)=224SA = 2(12 \cdot 4 + 12 \cdot 4 + 4 \cdot 4) = 2(48 + 48 + 16) = 2(112) = 224.
To calculate the total surface area of the prism.

Anahtar Kavram

Volume and Surface Area of Rectangular Prisms
Soru 29Soru

A right circular cylinder has a height of 12 centimeters12\text{ centimeters}. If the total surface area of the cylinder is 170π square centimeters170\pi\text{ square centimeters}, what is the volume, in cubic centimeters, of the cylinder?

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Cevap: 300π300\pi

Cevap

The volume of the cylinder is 300π300\pi cubic centimeters.
The correct answer is the volume of 300π300\pi cubic centimeters. We find this by using the cylinder's surface area equation 2πrh+2πr2=170π2\pi r h + 2\pi r^2 = 170\pi with h=12h = 12, which reduces to r2+12r85=0r^2 + 12r - 85 = 0. Factoring this equation gives the radius r=5r = 5. Plugging r=5r = 5 and h=12h = 12 into the volume formula V=πr2hV = \pi r^2 h gives 300π300\pi.

Adım Adım Çözüm

1
Set up the formula for the total surface area of a cylinder and plug in the given values.
2πrh+2πr2=170π2\pi r h + 2\pi r^2 = 170\pi, where h=12h = 12. This simplifies to 2πr(12)+2πr2=170π2\pi r(12) + 2\pi r^2 = 170\pi, or 24πr+2πr2=170π24\pi r + 2\pi r^2 = 170\pi.
We need to find the radius of the cylinder to calculate its volume.
2
Divide the entire equation by 2π2\pi to simplify it into a standard quadratic form.
r2+12r85=0r^2 + 12r - 85 = 0.
Simplifying the equation makes it easier to solve for the radius rr.
3
Factor the quadratic equation to find the positive value of the radius rr.
(r+17)(r5)=0(r + 17)(r - 5) = 0, which gives r=5r = 5 since the radius must be positive (r>0r > 0).
Factoring allows us to solve for the variable rr.
4
Use the radius r=5r = 5 and height h=12h = 12 to compute the volume of the cylinder.
V=πr2h=π(52)(12)=25×12π=300πV = \pi r^2 h = \pi (5^2)(12) = 25 \times 12 \pi = 300\pi cubic centimeters.
The volume formula for a cylinder is V=πr2hV = \pi r^2 h.

Anahtar Kavram

Calculating volume from total surface area for a cylinder by solving a quadratic relation.
Soru 30Soru

A trapezoid has parallel bases of length 66 centimeters and 1010 centimeters, and a height of 55 centimeters. What is the area, in square centimeters, of the trapezoid?

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Cevap: 40

Cevap

The area of the trapezoid is 4040 square centimeters.
The area of a trapezoid is calculated using the formula A=a+b2hA = \frac{a + b}{2} h, where aa and bb are the lengths of the parallel bases and hh is the height. Substituting the given values a=6a = 6, b=10b = 10, and h=5h = 5 into the formula yields A=6+102×5=8×5=40A = \frac{6 + 10}{2} \times 5 = 8 \times 5 = 40.

Adım Adım Çözüm

1
Recall the area formula for a trapezoid.
A=a+b2hA = \frac{a + b}{2}h
The area of a trapezoid is the average of its parallel bases multiplied by its height.
2
Substitute the base values of 66 and 1010, and the height value of 55 into the formula.
A=6+102×5A = \frac{6 + 10}{2} \times 5
This sets up the calculation with the given measurements.
3
Simplify the expression to find the final area.
A=40A = 40
Adding the bases gives 1616, dividing by 22 gives 88, and multiplying by the height of 55 results in 4040.

Anahtar Kavram

Area of a Trapezoid
Tahmini Süre:45s
Soru 31Soru

In right triangle ABCABC, the measure of angle BB is 9090^\circ. If sin(A)=513\sin(A) = \frac{5}{13}, what is the value of cos(C)\cos(C)?

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Cevap: 513\frac{5}{13}

Cevap

513\frac{5}{13}
The correct answer is 513\frac{5}{13}. In any right triangle ABCABC where the right angle is at BB, the two acute angles AA and CC are complementary, meaning A+C=90A + C = 90^\circ. The co-function identity states that the sine of an acute angle is equal to the cosine of its complement, or sin(A)=cos(90A)=cos(C)\sin(A) = \cos(90^\circ - A) = \cos(C). Given that sin(A)=513\sin(A) = \frac{5}{13}, the value of cos(C)\cos(C) must also be 513\frac{5}{13}.

Adım Adım Çözüm

1
Identify the relationship between the acute angles in a right triangle.
Since the measure of angle BB is 9090^\circ, the sum of the measures of angles AA and CC must be 9090^\circ. Thus, angles AA and CC are complementary.
The sum of angles in any triangle is 180180^\circ.
2
Apply the co-function identity for complementary angles.
For any two complementary angles AA and CC, the identity cos(C)=sin(A)\cos(C) = \sin(A) holds true.
The sine of an angle is the ratio of the opposite side to the hypotenuse, which is the same as the ratio of the adjacent side of its complement to the hypotenuse (cosine of the complement).
3
Substitute the given value to find cos(C)\cos(C).
Since sin(A)=513\sin(A) = \frac{5}{13}, it follows that cos(C)=513\cos(C) = \frac{5}{13}.
Direct substitution into the identity cos(C)=sin(A)\cos(C) = \sin(A).

Anahtar Kavram

Co-function identities for complementary angles in a right triangle
Soru 32Soru

A right circular cylindrical container with a base radius of RR inches is partially filled with water. A solid metal sphere with a radius of rr inches is placed into the container and becomes completely submerged, causing the water level to rise by 1.51.5 inches without any water overflowing. The sphere is then removed, and a solid right circular cone with a base radius of rr inches and a height of 1212 inches is placed vertex-down into the container. When the cone is completely submerged, the water level is 11 inch higher than the container's original water level. What is the value of RR, in inches?

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Cevap: 9

Cevap

The radius of the cylinder, RR, is 99 inches.
The volume of a submerged solid is equal to the volume of the cylinder of water it displaces. By setting up equations for the sphere and the cone, we get 43r3=1.5R2\frac{4}{3}r^3 = 1.5 R^2 and 4r2=R24r^2 = R^2. Substituting the second equation into the first yields r=4.5r = 4.5, which then gives R=2r=9R = 2r = 9.

Adım Adım Çözüm

1
Equate the volume of the sphere to the volume of water it displaces in the cylinder.
43πr3=1.5πR2    43r3=1.5R2\frac{4}{3}\pi r^3 = 1.5\pi R^2 \implies \frac{4}{3}r^3 = 1.5 R^2
The volume of a submerged solid equals the volume of the fluid it displaces. The displaced fluid takes the shape of a cylinder of radius RR and height equal to the water level rise (1.51.5 inches).
2
Equate the volume of the cone to the volume of water it displaces in the cylinder.
13πr2(12)=1.0πR2    4r2=R2\frac{1}{3}\pi r^2 (12) = 1.0\pi R^2 \implies 4r^2 = R^2
Similarly, the volume of the cone is equal to the volume of a cylinder of radius RR and height equal to the water level rise (11 inch).
3
Solve the system of equations by substituting R2R^2 into the sphere's displacement equation.
43r3=1.5(4r2)    43r3=6r2    r=4.5\frac{4}{3}r^3 = 1.5(4r^2) \implies \frac{4}{3}r^3 = 6r^2 \implies r = 4.5
By replacing R2R^2 with 4r24r^2, we reduce the system of equations to a single equation containing only rr. Since r0r \neq 0, we can divide by r2r^2 to solve for rr directly.
4
Calculate the value of RR from the relationship between RR and rr.
R=2r=2(4.5)=9R = 2r = 2(4.5) = 9
Since R2=4r2R^2 = 4r^2 and radii must be positive quantities, R=2rR = 2r.

Anahtar Kavram

Using water displacement to relate the volumes of three-dimensional geometric solids (cylinders, spheres, cones) and solving non-linear systems of equations.
Soru 33Soru

A container in the shape of a right circular cylinder with a base radius of 44 inches and a height of 99 inches is completely filled with water. All of the water from this cylinder is poured into an empty container in the shape of a rectangular prism. The rectangular prism container has a square base of side length 66 inches and a height of 1515 inches. If the height of the water in the rectangular prism container is kπk\pi inches, what is the value of kk?

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Cevap: 4

Cevap

The value of kk is 44.
To find the height of the water in the rectangular prism, we first calculate the volume of the water using the cylinder's volume formula, V=πr2hV = \pi r^2 h. With a radius of 44 inches and a height of 99 inches, the volume is π(4)2(9)=144π\pi (4)^2 (9) = 144\pi cubic inches. When this water is poured into the rectangular prism, the volume of the water can also be represented as the area of the base times the height of the water: V=Base Area×hw=62×hw=36hwV = \text{Base Area} \times h_w = 6^2 \times h_w = 36 h_w. Equating the two volumes gives 36hw=144π36 h_w = 144\pi, which simplifies to hw=4πh_w = 4\pi inches. Since the height of the water in the prism is kπk\pi inches, the value of kk is 44.

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1
Calculate the volume of the water in the filled cylinder using the formula V=πr2hV = \pi r^2 h.
The volume of the water is 144π144\pi cubic inches.
Since the cylinder is completely filled, the volume of the water is equal to the volume of the cylinder with base radius 44 inches and height 99 inches.
2
Calculate the area of the square base of the rectangular prism container.
The base area is 3636 square inches.
The base of the prism is a square with side length 66 inches, so its area is 6×6=366 \times 6 = 36 square inches.
3
Set the volume of the water in the rectangular prism equal to the volume of the water from the cylinder, and solve for the water height hwh_w.
36×hw=144π    hw=4π36 \times h_w = 144\pi \implies h_w = 4\pi inches.
Pouring the water into the prism container does not change its volume, which remains 144π144\pi cubic inches. The volume of a prism is the base area times its height.
4
Compare the height of the water 4π4\pi to the expression kπk\pi to find kk.
k=4k = 4.
Since the height of the water is represented as kπk\pi inches and we calculated it to be 4π4\pi inches, kk must equal 44.

Anahtar Kavram

Equating the volumes of a right circular cylinder and a rectangular prism to solve for an unknown dimension.
Soru 34Soru

A solid metal right circular cylinder has a base radius of 12 centimeters12\text{ centimeters} and a height of 3 centimeters3\text{ centimeters}. A cone with the same base and height as the cylinder is carved out and removed. The remaining metal is melted and recast into a solid sphere. What is the radius, in centimeters, of the sphere?

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Cevap: 6

Cevap

The radius of the sphere is 6 centimeters.
The volume of a cylinder is V=πr2h=π(12)2(3)=432πV = \pi r^2 h = \pi (12)^2 (3) = 432\pi. The volume of the carved-out cone is V=13πr2h=13π(12)2(3)=144πV = \frac{1}{3}\pi r^2 h = \frac{1}{3}\pi (12)^2 (3) = 144\pi. Subtracting the cone's volume from the cylinder's volume yields the remaining metal volume: 432π144π=288π432\pi - 144\pi = 288\pi. The volume of the recast sphere is 43πR3=288π\frac{4}{3}\pi R^3 = 288\pi. Dividing by π\pi and multiplying by 34\frac{3}{4} gives R3=216R^3 = 216. Taking the cube root of both sides gives the radius R=6R = 6.

Adım Adım Çözüm

1
Calculate the volume of the original cylinder.
432π cubic centimeters432\pi\text{ cubic centimeters}
This determines the starting volume of the solid metal block before any material is removed.
2
Calculate the volume of the cone that is carved out.
144π cubic centimeters144\pi\text{ cubic centimeters}
This determines how much metal is discarded from the cylinder.
3
Subtract the cone's volume from the cylinder's volume.
288π cubic centimeters288\pi\text{ cubic centimeters}
This gives the volume of the remaining metal that will be melted and recast.
4
Equate the remaining volume to the volume formula of a sphere and solve for the radius.
6 centimeters6\text{ centimeters}
This yields the radius of the newly formed sphere.

Anahtar Kavram

Volume of composite solids and conservation of volume during recasting
Soru 35Soru

A solid right circular cone has a base radius of 6 centimeters6\text{ centimeters} and a height of 8 centimeters8\text{ centimeters}. A sphere is inscribed inside the cone such that it is tangent to the base of the cone and tangent to the lateral surface of the cone. What is the ratio of the volume of the sphere to the volume of the cone?

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Cevap: 38\frac{3}{8}

Cevap

The ratio of the volume of the sphere to the volume of the cone is 38\frac{3}{8}.
The correct answer is found by first determining the radius of the inscribed sphere. By analyzing the 2D cross-section of the cone, which is an isosceles triangle with a base of 1212 and a height of 88, the slant height is found to be 1010 using the Pythagorean theorem. The radius of the inscribed circle (the sphere's radius) is calculated using the area and semiperimeter of the triangle, yielding R=3R = 3. The volume of the sphere is 36π36\pi and the volume of the cone is 96π96\pi. Dividing the sphere's volume by the cone's volume gives the ratio of 38\frac{3}{8}.

Adım Adım Çözüm

1
Find the slant height of the cone.
Slant height L=10 centimetersL = 10\text{ centimeters}.
The vertical cross-section of the cone is an isosceles triangle with base 2r=122r = 12 and height h=8h = 8. The slant height is the hypotenuse of the right triangle formed by the radius, height, and slant height: L=62+82=10L = \sqrt{6^2 + 8^2} = 10.
2
Calculate the radius of the inscribed sphere.
Sphere radius R=3 centimetersR = 3\text{ centimeters}.
The sphere's radius is the inradius of the cross-sectional isosceles triangle. The area of this triangle is A=12×12×8=48A = \frac{1}{2} \times 12 \times 8 = 48, and its semiperimeter is s=12+10+102=16s = \frac{12 + 10 + 10}{2} = 16. Using the inradius formula R=AsR = \frac{A}{s}, we get R=4816=3R = \frac{48}{16} = 3.
3
Calculate the volume of the cone.
Volume of the cone Vcone=96π cubic centimetersV_{\text{cone}} = 96\pi\text{ cubic centimeters}.
Using the volume of a cone formula, Vcone=13πr2h=13π(62)(8)=96πV_{\text{cone}} = \frac{1}{3}\pi r^2 h = \frac{1}{3}\pi (6^2)(8) = 96\pi.
4
Calculate the volume of the sphere.
Volume of the sphere Vsphere=36π cubic centimetersV_{\text{sphere}} = 36\pi\text{ cubic centimeters}.
Using the volume of a sphere formula, Vsphere=43πR3=43π(33)=36πV_{\text{sphere}} = \frac{4}{3}\pi R^3 = \frac{4}{3}\pi (3^3) = 36\pi.
5
Compute the ratio of the volume of the sphere to the volume of the cone.
Ratio =38= \frac{3}{8}.
Divide the volume of the sphere by the volume of the cone: 36π96π=3696=38\frac{36\pi}{96\pi} = \frac{36}{96} = \frac{3}{8}.

Anahtar Kavram

Calculating the volume of spheres and cones, and using 2D cross-sections to find missing geometric dimensions of inscribed solids.
Soru 36Soru

A circular rug has an area of 16π16\pi square feet. If the radius of the rug is tripled, what is the area, in square feet, of the new rug?

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Cevap: 144π144\pi

Cevap

The area of the new rug is 144π144\pi square feet.
The area of a circle scales with the square of its radius. If the radius is tripled, the area is multiplied by 32=93^2 = 9. Since the original area is 16π16\pi square feet, the area of the new rug is 16π×9=144π16\pi \times 9 = 144\pi square feet.

Adım Adım Çözüm

1
Determine the relationship between the linear scale factor and the area scale factor of a circle.
If the radius of a circle is multiplied by a scale factor kk, the area of the circle is multiplied by k2k^2.
The area of a circle is proportional to the square of its radius (A=πr2A = \pi r^2).
2
Find the area scale factor when the radius is tripled.
Since the radius is multiplied by 33, the area scale factor is 32=93^2 = 9.
Squaring the linear scale factor of 3 gives the quadratic scale factor for the area.
3
Calculate the area of the new rug.
The new area is 16π×9=144π16\pi \times 9 = 144\pi square feet.
Multiplying the original area of 16π16\pi square feet by the area scale factor of 9 yields the final scaled area.

Anahtar Kavram

Area scaling of two-dimensional shapes
Tahmini Süre:1m 0s
Soru 37Soru

Two straight support beams on a bridge intersect at a single point. One of the angles formed by their intersection measures 7474^\circ. An adjacent angle along the straight line of one of the beams has a measure of (2x+16)(2x + 16)^\circ. What is the value of xx?

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Cevap: 45

Cevap

45
Since the two angles form a linear pair along a straight support beam, their measures must sum to 180180^\circ. We can write the equation as 74+(2x+16)=18074 + (2x + 16) = 180. Combining like terms gives 2x+90=1802x + 90 = 180. Subtracting 9090 from both sides yields 2x=902x = 90. Finally, dividing by 22 gives x=45x = 45.

Adım Adım Çözüm

1
Set up the equation using the property of supplementary angles.
74+(2x+16)=18074 + (2x + 16) = 180
Adjacent angles on a straight line form a linear pair, which means they are supplementary and sum to 180180^\circ.
2
Combine the constant terms on the left side of the equation.
2x+90=1802x + 90 = 180
Adding 7474 and 1616 simplifies the constant terms to 9090.
3
Isolate the variable term by subtracting 90 from both sides of the equation.
2x=902x = 90
Subtracting 9090 from 180180 leaves 9090 on the right side.
4
Solve for x by dividing both sides of the equation by 2.
x=45x = 45
Dividing 2x2x and 9090 by 22 isolates the variable xx.

Anahtar Kavram

Adjacent angles on a straight line are supplementary and add up to 180 degrees.
Tahmini Süre:45s
Soru 38Soru

If sin(x)=cos(38)\sin(x^\circ) = \cos(38^\circ), where 0<x<900 < x < 90, what is the value of xx?

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Cevap: 52

Cevap

The value of xx is 52.
Applying the co-function identity sin(θ)=cos(90θ)\sin(\theta) = \cos(90^\circ - \theta) allows us to set the argument of the sine function as the complement of the cosine's argument. Thus, x=9038=52x = 90 - 38 = 52.

Adım Adım Çözüm

1
Identify the relevant trigonometric identity.
The co-function identity sin(x)=cos(90x)\sin(x^\circ) = \cos(90^\circ - x^\circ) is appropriate here.
We need to relate the sine of one angle to the cosine of another angle.
2
Equate the angle arguments using the identity.
sin(x)=cos(90x)=cos(38)\sin(x^\circ) = \cos(90^\circ - x^\circ) = \cos(38^\circ), which implies 90x=3890 - x = 38.
For acute angles, if their cosine values are equal, the angles themselves must be equal.
3
Solve the linear equation for xx.
x=9038=52x = 90 - 38 = 52.
Isolating xx gives the final answer.

Anahtar Kavram

Co-function identities relate the sine of an angle to the cosine of its complement: sin(θ)=cos(90θ)\sin(\theta) = \cos(90^\circ - \theta).
Soru 39Soru

In right triangle XYZXYZ, the measure of angle YY is 9090^\circ, XY=12XY = 12, and YZ=5YZ = 5. What is the value of cos(X)sin(X)\cos(X) - \sin(X)?

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Cevap: 713\frac{7}{13}

Cevap

713\frac{7}{13}
The length of the hypotenuse XZXZ is first found using the Pythagorean theorem: XZ=122+52=13XZ = \sqrt{12^2 + 5^2} = 13. Using the definitions of the trigonometric ratios, cos(X)=adjacenthypotenuse=1213\cos(X) = \frac{\text{adjacent}}{\text{hypotenuse}} = \frac{12}{13} and sin(X)=oppositehypotenuse=513\sin(X) = \frac{\text{opposite}}{\text{hypotenuse}} = \frac{5}{13}. The difference is cos(X)sin(X)=1213513=713\cos(X) - \sin(X) = \frac{12}{13} - \frac{5}{13} = \frac{7}{13}.

Adım Adım Çözüm

1
Find the length of the hypotenuse XZXZ using the Pythagorean theorem.
XZ=XY2+YZ2=122+52=144+25=169=13XZ = \sqrt{XY^2 + YZ^2} = \sqrt{12^2 + 5^2} = \sqrt{144 + 25} = \sqrt{169} = 13.
The hypotenuse is needed as the denominator for the sine and cosine ratios.
2
Determine the values of cos(X)\cos(X) and sin(X)\sin(X).
cos(X)=XYXZ=1213\cos(X) = \frac{XY}{XZ} = \frac{12}{13} and sin(X)=YZXZ=513\sin(X) = \frac{YZ}{XZ} = \frac{5}{13}.
By definition, cos(θ)=adjacenthypotenuse\cos(\theta) = \frac{\text{adjacent}}{\text{hypotenuse}} and sin(θ)=oppositehypotenuse\sin(\theta) = \frac{\text{opposite}}{\text{hypotenuse}}.
3
Calculate the difference cos(X)sin(X)\cos(X) - \sin(X).
cos(X)sin(X)=1213513=713\cos(X) - \sin(X) = \frac{12}{13} - \frac{5}{13} = \frac{7}{13}.
This is the final subtraction requested by the question.

Anahtar Kavram

Calculating trigonometric ratios in a right triangle and applying basic operations.
Soru 40Soru

A triangular banner has an area of 3030 square feet. If the height of the banner is 55 feet, what is the length, in feet, of the base of the banner?

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Cevap: 12

Cevap

The length of the base of the banner is 1212 feet.
To find the base of the triangular banner, apply the formula for the area of a triangle: A=12bhA = \frac{1}{2} b h. Substituting 3030 for the area AA and 55 for the height hh yields 30=12b(5)30 = \frac{1}{2} b (5), or 30=2.5b30 = 2.5b. Dividing both sides of the equation by 2.52.5 gives b=12b = 12. Therefore, the length of the base of the banner is 1212 feet.

Adım Adım Çözüm

1
Recall the formula for the area of a triangle.
A=12bhA = \frac{1}{2} b h
The area of a triangle is equal to half the product of its base and height.
2
Substitute the given values into the area formula.
30=12×b×530 = \frac{1}{2} \times b \times 5
The problem provides the area (3030 square feet) and the height (55 feet).
3
Solve for the base bb.
b=12b = 12
Multiply both sides of the equation by 22 to clear the fraction, giving 60=5b60 = 5b. Then, divide both sides by 55 to find that b=12b = 12.

Anahtar Kavram

Area of a triangle
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Geometry and Trigonometry Alıştırma Soruları — SAT — Sayfa 2 | Examkin