A boy of mass 60.0 kg is rescued from a hotel fire by leaping into a firefighters' net. The window from which he leapt was 8.0 m above the net. The firefight- ers lower their arms as he lands in the net so that he is brought to a complete stop in a time of 0.40 s.
(a) What is his change in momentum during the 0.40-s interval?
(b) What is the impulse on the net due to the boy during the interval? [Hint: Do not ignore gravity.]
(c) What is the average force on the net due to the boy during the interval?