## Calculus 8th Edition

$2400 (cos 40 ^\circ) \approx 1839$ ft-lb
Horizontal component of the force is: $|F|cos 40 ^\circ$ $F=30 lb$ and $d =80 ft$ As we know the work done is calculated as: $W=| F||d| cos 40^\circ$ Thus, $W=( 30 lb) (80 ft) (cos 40 ^\circ)$ $W= 2400 (cos 40 ^\circ) \approx 1839$ ft-lb