Question

An elephant lifts 7 large logs from the ground to a container 5 meters above the ground as part of a zoo demonstration. The elephant exerted a force of 250 Newtons to lift each log. How much work did the elephant do altogether? A. 1250 J B. 1750 J C. 7880 J D. 8750 J

Answer 1

The work done by the elephant to lift one log is the force multiplied by the height at which the log has been lifted:
$W=Fh=250 N \cdot 5 m=1250 J$
And so, the total work done to lift the 7 logs is 7 times the work done to lift each log:
$W_t = 7 W=7 \cdot 1250 N=8750 J$