A hollow cylindrical copper pipe is 140 m long and has an ou

A hollow cylindrical copper pipe is 1.40 m long and has an outside diameter of 3.30 cm and an inside diameter of 2.70 cm.

Part A

How much does it weigh?

Please show all your work.

Solution

L = 1.40 m
do = 3.30 cm
di = 2.70 cm
The density of copper is 8960 kg/m^3

Ro = 3.30/2 = 1.65 cm
Ri = 2.70/2 = 1.35 cm

Volume of the cylinder, V = *(Ro^2 - Ri^2)*L
V = *((1.65*10^-2)^2 - (1.35*10^-2)^2) * 1.4
V = 3.96 * 10^-4 m^3

Density = Mass/Volume
Mass = Density * Volume
Mass = 8960 *  3.96 * 10^-4
M = 3.55 Kg

Weight = M*g
Weight = 3.55 * 9.8 N
Weight =  34.8 N