1. The problem statement, all variables and given/known data A 25 kg bear slides, from rest, 8 m down a lodgepole pine tree, moving with a speed of 6.4 m/s just before hitting the ground (a) What change occurs in the gravitational potential energy of the bear-Earth system during the slide? W = F*D W = (m*a)*D W = 1960 (b) What is the kinetic energy of the bear just before hitting the ground? KE = 0.5*m*v^2 KE = 512 (c) What is the average frictional force that acts on the bear? Ei = m*g*h = 1960 Ef = 0.5*m*v^2 W = -Fk*h Ei + W = Ef 1960 + (-Fk*h) = 512 -Fk = 120.67 Could someone check to see if i solved this correctly? Thanks!