Question

A semi-circle with a diameter of 4 is rotated around its diameter one full rotation, what is the volume of the solid generated by the revolution?

Answer 1

The volume of the solid generated by the revolution is 33.5 cubic units.

Step-by-step explanation:

It is given that, the diameter of the semi-circle is 4 and it is rotated to one full rotation around its diameter.

A solid generated when a semicircle is being rotated about its diameter is called a "SPHERE".

Therefore, the volume of the solid generated by the revolution is the volume of the sphere.

The formula for volume of the sphere is given by,

Volume of sphere = (4/3)πr³

where, r is the radius and π has the default value of 3.14

Here, the given diameter is 4.

To find the radius = diameter/2

radius = 4/2 = 2.

Now, to calculate volume of sphere substitute r=2 and π=3.14

volume of the sphere = (4/3)×3.14×2³

⇒ (4/3)×3.14×8

⇒ 100.48 / 3

⇒ 33.49 (approximately 33.5)

Therefore, the volume of the solid generated by the revolution is 33.5 cubic units.