Starting from rest, a 1.8 10-4-kg flea springs straight upward.
While the flea is pushing off from the ground, the ground exerts an
average upward force of 0.39 N on it. This force does +2.3 10-4 J
of work on the flea.
(a) What is the flea's speed when it leaves the ground? m/s
(b) How far upward does the flea move while it is pushing off?
Ignore both air resistance and the flea's weight. m