Question

Helppp pleaseeeee The object below is made of solid plastic. It is a cylinder with an indentation at the top in the shape of a cone.What is the volume, to the nearest tenth of a cubic inch, of the plastic object? Explain your answer.

Answer 1

Answer:

Total volume = (145/3)π in³

Step-by-step explanation:

First find the volume of the entire cylinder.  The correct formula to use here is:

V = πr²h, where r is the radius and h is the height.  Here, with the radius being 5/2 inches and the height being 8 inches, the cylinder volume is

V = π(2.5 in)²(8 in) = 50π in³

Next find the volume of the conical shape:  V = (1/3)π(2.5 in)²(0.8 in)

The desired volume is equal to the volume of the entire cylinder LESS the volume of the cone:

π(2.5 in)²(8 in) = 50π in³  LESS  (1/3)π(2.5 in)²(0.8 in), which simplifies as follows:

Total volume =

50 π in³ -  (1/3)π(2.5 in)²(0.8 in), or

(2.5 in)²π[8 in - 0.8/3 in] =  π(6.25 in²)(8 in - 8/30 in) = π( 6.25 in²)(116/15 in), or

Total volume = (145/3)π in³