How to Find the Volume of a Sphere
Finding the Volume of a Sphere
The volume of a sphere is found using the formula:
In this formula, r is the radius of the sphere. The image below shows what we mean by radius:
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How to Find the Volume of a Sphere
Question
What is the volume of a sphere with a radius of 5 cm, as shown below?
Step-by-Step:
1
Start with the formula:
Volume = 4πr3 ⁄ 3
Don't forget: π is pi (≈ 3.14) and r3 = r × r × r (r cubed) and ⁄ means ÷.
2
Substitute the radius into the formula. In our example, r = 5.
Volume = 4 × π × 53 ⁄ 3
Volume = 4 × π × 125 ÷ 3
Volume = 4 × 3.14 × 125 ÷ 3
Volume = 523.3 cm3
Answer:
The volume of the sphere with a radius of 5 cm is 523.3 cm3.
See Also
What is the radius?Interactive Test
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Here's a second test on finding the volume of a sphere
Here's a third test on finding the volume of a sphere
Note
What Is a Sphere?
A sphere is a ball-shaped object. Each point on its surface is the same distance away from the center.
The Main Parts of a Sphere
The radius is the distance from the center of a sphere to its surface.
The diameter is the line that goes through the center of the sphere and joins two opposite points on the surface. It is twice the length of the radius.
Who Discovered How To Find the Volume of a Sphere?
Archimedes discovered was the first to prove the volume of a sphere.
A Sphere in a Cylinder
If a sphere is placed in a cylinder, the volume of the sphere is exactly two-thirds the volume of the cylinder.
Can you work out why?