All ACT Math Resources
Example Questions
Example Question #1 : How To Find The Surface Area Of A Sphere
What is the surface area of a sphere that has a diameter of eight inches? Reduce any fractions in your answer and leave your answer in terms of .
To find the volume of a sphere area of a sphere plug the radius into the following formula given by :
.
To find the radius given the diameter, divide the diameter by 2.
Thus:
Example Question #2 : How To Find The Surface Area Of A Sphere
What is the surface area of a sphere, in inches, that has a surface area equal to its volume? Leave your answer in terms of .
To find the radius of a sphere that has a volume equal to it's surface area, begin by setting the volume and surface area formulas for a sphere equal to each other and solving for the radius:
Next we plug the answer for our radius into the formula for the surface area:
, remember to check the units.
Example Question #3 : How To Find The Surface Area Of A Sphere
Find the surface area of a sphere whose radius is .
To solve, simply remember the following formula:
Example Question #733 : Geometry
Find the surface area of a sphere whose radius is . Thus,
To find surface area, simply use the formula. Thus,
Example Question #2 : How To Find The Surface Area Of A Sphere
Find the surface area of a sphere whose side diameter is .
To solve, simply use the following formula for the surface area of a circle. Thus,
Example Question #1 : How To Find The Volume Of A Sphere
For a sphere the volume is given by V = (4/3)πr3 and the surface area is given by A = 4πr2. If the sphere has a surface area of 256π, what is the volume?
750π
615π
300π
683π
683π
Given the surface area, we can solve for the radius and then solve for the volume.
4πr2 = 256π
4r2 = 256
r2 = 64
r = 8
Now solve the volume equation, substituting for r:
V = (4/3)π(8)3
V = (4/3)π*512
V = (2048/3)π
V = 683π
Example Question #1 : Spheres
The specifications of an official NBA basketball are that it must be 29.5 inches in circumference and weigh 22 ounces. What is the approximate volume of the basketball? Remember that the volume of a sphere is calculated by V=(4πr3)/3
138.43 cu.in.
8557.46 cu.in.
3468.05 cu.in.
92.48 cu.in.
434.19 cu.in.
434.19 cu.in.
To find your answer, we would use the formula: C=2πr. We are given that C = 29.5. Thus we can plug in to get [29.5]=2πr and then multiply 2π to get 29.5=(6.28)r. Lastly, we divide both sides by 6.28 to get 4.70=r. Then we would plug into the formula for volume V=(4π〖(4.7)〗3) / 3 (The information given of 22 ounces is useless)
Example Question #11 : Spheres
The radius of a sphere is . What is the approximate volume of this sphere?
Example Question #12 : Spheres
A cube has a side dimension of 4. A sphere has a radius of 3. What is the volume of the two combined, if the cube is balanced on top of the sphere?
Example Question #1 : Spheres
What is the volume of a sphere with a diameter of 6 in?
The formula for the volume of a sphere is:
where = radius. The diameter is 6 in, so the radius will be 3 in.
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