SSAT Upper Level Math : Volume of a Three-Dimensional Figure

Study concepts, example questions & explanations for SSAT Upper Level Math

varsity tutors app store varsity tutors android store

Example Questions

Example Question #1 : How To Find The Volume Of A Sphere

A car dealership wants to fill a large spherical advertising ballon with helium. It can afford to buy 1,000 cubic yards of helium to fill this balloon. What is the greatest possible diameter of that balloon (nearest tenth of a yard)?

Possible Answers:

\displaystyle 9.3 \;\textrm{yd}

\displaystyle 15.4 \;\textrm{yd}

\displaystyle 6.2 \;\textrm{yd}

\displaystyle 12.4 \;\textrm{yd}

\displaystyle 7.7 \;\textrm{yd}

Correct answer:

\displaystyle 12.4 \;\textrm{yd}

Explanation:

The volume of a sphere, given its radius, is 

\displaystyle V = \frac{4\pi r^{3}}{3}

Set \displaystyle V = 1,000, solve for \displaystyle r, and double that to get the diameter.

\displaystyle 1,000= \frac{4\pi r^{3}}{3}

\displaystyle r^{3} = \frac{1,000 \cdot 3 }{4\pi} \approx 238.7

\displaystyle r \approx \sqrt[3]{238.7} \approx 6.2

The diameter is twice this, or 12.4 yards.

Example Question #2 : How To Find The Volume Of A Sphere

The diameter of a sphere is \displaystyle 6t. Give the volume of the sphere in terms of \displaystyle t.

Possible Answers:

\displaystyle 36\pi t^3

\displaystyle 72\pi t^3

\displaystyle 30\pi t^3

\displaystyle 24\pi t^3

\displaystyle 10\pi t^3

Correct answer:

\displaystyle 36\pi t^3

Explanation:

The diameter of a sphere is \displaystyle 6t so the radius of the sphere would be \displaystyle 6t\div 2=3t

 

The volume enclosed by a sphere is given by the formula:

\displaystyle Volume=\frac{4}{3}\pi r^3=\frac{4}{3}\pi \times (3t)^3=\frac{4}{3}\pi\times 27t^3\Rightarrow Volume=36\pi t^3 

 

 

Example Question #3 : How To Find The Volume Of A Sphere

A spherical balloon has a diameter of 10 meters. Give the volume of the balloon.

Possible Answers:

\displaystyle 723.3m^3

\displaystyle 500m^3

\displaystyle 1000m^3

\displaystyle 523.6m^3

\displaystyle 1023.3m^3

Correct answer:

\displaystyle 523.6m^3

Explanation:

The volume enclosed by a sphere is given by the formula:

\displaystyle Volume=\frac{4}{3}\pi r^3

where \displaystyle r is the radius of the sphere. The diameter of the balloon is 10 meters so the radius of the sphere would be \displaystyle 10\div 2=5 meters. Now we can get:

 

\displaystyle Volume=\frac{4}{3}\pi r^3=\frac{4}{3}\pi\times 5^3=\frac{4}{3}\times \pi \times 125\approx 523.6 m^3

Example Question #151 : Geometry

The volume of a sphere is 1000 cubic inches. What is the diameter of the sphere.

Possible Answers:

\displaystyle 12\ inches

\displaystyle 12.4\ inches

\displaystyle 10.4\ inches

\displaystyle 16.4\ inches

\displaystyle 10\ inches

Correct answer:

\displaystyle 12.4\ inches

Explanation:

The volume of a sphere is:

\displaystyle Volume=\frac{4}{3}\pi r^3

 

Where \displaystyle r is the radius of the sphere. We know the volume and can solve the formula for \displaystyle r:

 

\displaystyle Volume=\frac{4}{3}\pi r^3=1000\Rightarrow r^3=\frac{3\times1000 }{4\pi}\approx 238.85\Rightarrow r\approx 6.2 inches

 

So we can get:

 

\displaystyle Diameter=2r=2\times 6.2=12.4inches

Example Question #2 : Volume Of A Three Dimensional Figure

A sphere has a diameter of \displaystyle 10 inches. What is the volume of this sphere?

Possible Answers:

\displaystyle 104.7 \displaystyle in^3

\displaystyle 523.6 \displaystyle in^3

\displaystyle 458.3 \displaystyle in^3

\displaystyle 632.9 \displaystyle in^3

Correct answer:

\displaystyle 523.6 \displaystyle in^3

Explanation:

To find the volume of a sphere, use the following formula:

\displaystyle \text{Volume}=\frac{4}{3}\pi\times r^3, where \displaystyle r is the radius of the sphere.

Now, because we are given the diameter of the sphere, divide that value in half to find the radius.

\displaystyle r=10\div2=5 \displaystyle in

Now, plug this value into the volume equation.

\displaystyle \text{Volume}=\frac{4}{3}\pi\times 5^3

\displaystyle \text{Volume}=\frac{4}{3}\pi\times 125

\displaystyle \text{Volume}=\frac{500}{3}\pi=523.6 \displaystyle in^3 

Example Question #2 : Volume Of A Three Dimensional Figure

What is the volume of a sphere with a diameter of \displaystyle 10?

Possible Answers:

\displaystyle \frac{100}{3}\pi

\displaystyle 200\pi

\displaystyle 100\pi

\displaystyle 150\pi

\displaystyle \frac{500}{3}\pi

Correct answer:

\displaystyle \frac{500}{3}\pi

Explanation:

Write the formula for the volume of the sphere.

\displaystyle V=\frac{4}{3}\pi r^3

The radius is half the diameter, which is five.  Substitute the value.

\displaystyle V=\frac{4}{3}\pi r^3=\frac{4}{3}\pi (5)^3=\frac{4}{3}\pi (125)= \frac{500}{3}\pi

Example Question #4 : How To Find The Volume Of A Sphere

What is the volume of a sphere with diameter 12 feet?

Possible Answers:

\displaystyle 7,238.2\;ft^{3}

\displaystyle 904.8 ft^{3}

\displaystyle 452.4\;ft^{3}

None of the other answers are correct

\displaystyle 3,619.1\;ft^{2}

Correct answer:

\displaystyle 904.8 ft^{3}

Explanation:

The radius of the sphere is half the diameter, or 6 feet; use the formula

\displaystyle V= \frac{4}{3} \pi r^{3} .

Setting \displaystyle r=6:

 \displaystyle V= \frac{4}{3} \pi \cdot 6^{3} \approx904.8 ft^{3}

Example Question #1 : Volume Of A Three Dimensional Figure

Chestnut wood has a density of about \displaystyle 0.45\frac{g}{cm^3}. A right circular cone made out of chestnut wood has a height of three meters, and a base with a radius of two meters. What is its mass in kilograms (nearest whole kilogram)?

Possible Answers:

\displaystyle 5,955 \; \textrm{kg}

\displaystyle 6,055 \; \textrm{kg}

\displaystyle 5,655 \; \textrm{kg}

\displaystyle 5,855 \; \textrm{kg}

\displaystyle 5,755 \; \textrm{kg}

Correct answer:

\displaystyle 5,655 \; \textrm{kg}

Explanation:

First, convert the dimensions to cubic centimeters by multiplying by \displaystyle 100: the cone has height \displaystyle 300cm, and its base has radius \displaystyle 200cm.

Its volume is found by using the formula and the converted height and radius.

\displaystyle V=\frac{1}{3} \pi r^{2}h

\displaystyle V=\frac{1}{3} \pi (200cm)^{2} ( 300cm )\approx 12,566,371 \; \textrm{cm}^{3}

Now multiply this by \displaystyle 0.45\frac{g}{cm^3} to get the mass.

\displaystyle m=V*\rho

\displaystyle 12,566,371cm^3*0.45\frac{g}{cm^3} \approx 5,654,867g

Finally, convert the answer to kilograms.

\displaystyle 5654867g *\frac{1kg}{1,000g} \approx 5,655kg

Example Question #1 : How To Find The Volume Of A Cone

A cone has the height of 4 meters and the circular base area of 4 square meters. If we want to fill out the cone with water (density = \displaystyle 1000\frac{Kg}{m^3}), what is the mass of required water (nearest whole kilogram)?

Possible Answers:

\displaystyle 10,000

\displaystyle 5333

6333

\displaystyle 4333

\displaystyle 2133

Correct answer:

\displaystyle 5333

Explanation:

The volume of a cone is:

\displaystyle Volume=\frac{1}{3}\pi r^2h

where \displaystyle r is the radius of the circular base, and \displaystyle h is the height (the perpendicular distance from the base to the vertex).

 

As the circular base area is \displaystyle \pi r^2, so we can rewrite the volume formula as follows:

 

\displaystyle Volume =\frac{A\times h}{3}

 

where \displaystyle A is the circular base area and known in this problem. So we can write:

 

\displaystyle Volume =\frac{A\times h}{3}=\frac{4\times 4}{3}=\frac{16}{3}\approx 5.333 m^3

 

We know that density is defined as mass per unit volume or:

 

\displaystyle \rho =\frac{m}{v}

 

Where \displaystyle \rho is the density; \displaystyle m is the mass and \displaystyle v is the volume. So we get:

 

\displaystyle m=\rho v=1000\times 5.333=5333 Kg

Example Question #1 : Know And Use The Formulas For The Volumes Of Cones, Cylinders, And Spheres: Ccss.Math.Content.8.G.C.9

The vertical height (or altitude) of a right cone is \displaystyle 2t. The radius of the circular base of the cone is \displaystyle t. Find the volume of the cone in terms of \displaystyle t.

Possible Answers:

\displaystyle \frac{2}{3}\pi t^2

\displaystyle \frac{1}{3}\pi t^2

\displaystyle \frac{1}{3}\pi t^3

\displaystyle \frac{2}{3}\pi t^3

\displaystyle \pi t^3

Correct answer:

\displaystyle \frac{2}{3}\pi t^3

Explanation:

The volume of a cone is:

\displaystyle Volume=\frac{1}3{}\pi r^2h

 

where \displaystyle r is the radius of the circular base, and \displaystyle h is the height (the perpendicular distance from the base to the vertex).

 

\displaystyle Volume=\frac{1}3{}\pi r^2h =\frac{1}3{}\pi t^2\times 2t=\frac{2}{3}\pi t^3

Learning Tools by Varsity Tutors