SOLUTION: How much lead is needed to coat a cable, 55 mm in diameter, if the cable is 5 km long and the lead coat is 4 mm thick? Use 11.4 x 103 kg/m3 for the density of lead.

Algebra ->  Bodies-in-space -> SOLUTION: How much lead is needed to coat a cable, 55 mm in diameter, if the cable is 5 km long and the lead coat is 4 mm thick? Use 11.4 x 103 kg/m3 for the density of lead.       Log On


   

Question 949579: How much lead is needed to coat a cable, 55 mm in diameter, if the cable is 5 km long and the lead coat is 4 mm thick? Use 11.4 x 103 kg/m3 for the density of lead.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Model the coating to be like a cylinder with inside diameter 55 mm, outside diameter 55+8=63 mm, length 5 m.

Volume of lead, v=5%2Api%2A%280.063%2F2%29%5E2-5%2Api%2A%280.055%2F2%29%5E2
%285pi%2F4%29%280.063%5E2-0.055%5E2%29
%285pi%2F4%29%280.000944%29
highlight%280.00118pi%29 cubic meters.

The way you showed your lead's density looks strange, indicating to be 1174.2 kilograms per cubic meter, which may be the wrong value. You decide what you really want to use for the lead's density. Convert your volume into kilograms.