A cable weighing 2lbs/ft is used to lift 800 lbs of coal up a mineshaft 500 ft deep.Find out how much work is done in ft-lbs.

Question

$\begin{array}{1 1}650000\;ft-lbs\\400000\;ft-lbs\\250000\;ft-lbs\\450000\;ft-lbs\end{array}$