Question

If a 200 mg piece of gold is hammered into a sheet with an area of 2.4ft^2, what is the thickness of the sheet in meters? Density of gold is 19.32 g/cm^3 (1 ft = 2.54 cm, 12 in = 1 foot)? [I really need this spelled out using converstion factors. The other reply to this question does not help at all].

Answer 1

Area, A = 2.4 ft^2
                =2.4* (2.54)^2 cm^2
                = 15.48 cm^2  

Let thickness be t cm.

Then Volume = A*t
                             =15.48*t cm^3    

m = 200 mg = 0.2 g

use:
density = mass / volume
19.32 g/cm^3 = 0.2 g/ 15.48*t cm^3
15.48*t = 0.1035
t = 6.687*10^-4 cm
   =( 6.687*10^-4 ) / 2.54 ft
    =2.633*10^-4 ft
    =2.633*10^-4 * 12 in
    =0.00316 inch
Answer: 0.00316 in