A 0.145 kg baseball pitched at 39.0 m/s is hit on a horizontal line drive straight back towards the pitcher at 59.0 m/s. If the contact time between bat and ball is 0.001 s, calculate the average force between the ball and
bat contact. (NO Scientific Notation!)

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.