An 80 kg stuntman jumps from the top of a building 23 m above a catching net. Assuming that air resistance exerts a 100 N force on the stuntman as he falls, determine his velocity just before he hits the net.

Answer 1

(m)(g)(h)-(F)(d)=(1/2)(m)(v2^2)
mgh-(F)(d)=(1/2)(m)(v^2)
(80)(9.8)(23)-(100)(23)=(1/2)(80)(v^2)
18032-2300=(40)(v^2)
15732=(40)(v^2)
393.3=(v^2)
v=19.832 m/s