Question

A metal conduit will be used as a pathway for wiring through a concrete block. The conduit is a 4 foot long rod with an outer diameter of 2.2 inches and an inner diameter of 2 inches. What is the volume of metal in the conduit in cubic centimeters? ...?

Answer 1

Answer:$510. 12 cm^3$

The volume of a cylindrical conduit, $V=\pi (r_2^2-r_1^2) h$

where $r_1$ is the inner radius, $r_2$ is the outer radius, h is the length.

First of all, we would covert each parameter into centimeters.

length of the conduit, $h=4 ft=4\times 30.48 cm=121.92 cm$

outer radius, $r_1=2.2/2 in =1.1 in= 1.1\times 2.54 cm=2.79 cm$

inner radius, $r_1=2/2 in =1 in= 2.54 cm$

Insert the values in the volume formula,

$V=3.14 \times (2.79^2-2.54^2) \times 121.92 cm^3=510. 12 cm^3$

Hence, the volume of metal in the conduit is 510. 12 cubic centimeters.

Answer 2

We assume this conduit is in a cylindrical form. So that the volume can be calculated by the expression given as:

V=πr²h

However, we the conduit has a hollow space and this should not be included in the volume. We calculate as follows:

V(outer cylinder) = πr²h = π(2.2/2)²(4)(12) = 182.46 in³
V(inner cylinder ) = πr²h = π(2/2)²(4)(12) =  48π in³
V = 182.46 in³ - 48π in³ = 31.66 in³ ---->ANSWER