Chemistry
posted by Eliza .
What is the mass of a cylinder of lead that is 2.50 cm in diameter and 5.50 cm long. The density of lead is 11.4 g/mL. Find the volume of the cylinder.

Recall that density of a material can be solved by
d = m/V
where:
m = mass of material
V = volume of material
Note that the volume of a cylinder is given by
V = pi*(r^2)*h
where:
r = radius (which is 1/2 of the diameter)
h = height
Substituting,
V = 3.14*[(2.50/2)^2]*5.50
V = 26.98 cm^3
d = m/V
Note that mL is equivalent to cm^3. Thus
11.4 = m/26.98
m = 11.4*26.98
m = 307.57 g
Hope this helps~ :) 
307.57 g