Frictional Energy?? 1. The problem statement, all variables and given/known data A 145 g baseball is dropped from a tree 8.0 m above the ground. (b) If it actually hits the ground with a speed of 7.80 m/s, what is the magnitude of the average force of air resistance exerted on it? 2. Relevant equations I've tried this problem several times, but I do not know how to find air resistance using the energy of the problem. Any help would be appreciated! (air resistance) h= (delta)KE +(delta)PE 3. The attempt at a solution (air resistance)=(m(.5(v^2)-gh))/h Using this I got 5.56 N as an answer, but apparently that's wrong. Any help whatsoever is appreciated!