1. The problem statement, all variables and given/known data The coefficient of friction between the block of mass m1 = 3.00kg and the surface in Figure P7.22 is μk = 0.400. The system starts from rest. What is the speed of the ball of mass m2 = 5.00 kg when it has fallen a distance of h = 1.50m? 2. Relevant equations This is in the chapter on conservation of energy, so Ui + Ki + ΔEmech = Uf + Kf 3. The attempt at a solution Using downward direction as positive so g is positive m2gh - fh = 1/2(m1 + m2)v2 (5.00kg)(9.8m/s2)(1.5m) - (-11.76N)(1.5m) = 1/2(3.00kg + 5.00kg)v2 91.14Nm = 4kg * v2 22.785Nm2/s2 = v2 4.77m/s = v That's not the answer that I'm seeing on the answer sheet. I'm not sure what I did wrong.