Question

A cylindrical metal pipe has a diameter of 8.4 millimeters

Answer 1

Answer:

C. 271.44 $mm^3$

Step-by-step explanation:

We need to first find the volume of the pipe, then find the volume of the hole and then subtract the volume of the hole from the volume of the pipe.

The diameter of the pipe is 8.4 mm. This means its radius is:

8.4/2 = 4.2 mm

The height of the pipe is 10 mm

The volume of a cylinder is given as:

$V = \pi r^2h$

where r = radius

h - height

Therefore, the volume of the cylinder  without the hole is:

$V = \pi * 4.2^2 * 10\\\\V = 554.18 mm^3$

The diameter of the hole is 6 mm. Its radius is:

6/2 = 3 mm

The volume of the hole is:

$V = \pi * 3^2 * 10\\\\V = 282.74 mm^3$

The volume is:

554.18 - 282.74 = 271.44 $mm^3$

Answer 2

Answer:

B. 271.3 $mm^{3}$

Step-by-step explanation:

Volume of the outer cylinder minus the volume of the inner cylinder returns the volume of the metal outer ring that surrounds the hole.