Two rowboats on a lake are lined up, in contact, front to back in the same direction. A passenger in the rear boat pushes the front boat directly forward with a force of 40 N. How much force does the front boat exert on the rear boat?

A. 0N
B. 20N
C. 40N
D. 80N

An insulated thermos contains 148 g of water at 72.7 ˚c. you put in a 11.7 g ice cube at 0.00 ˚c to form a system of ice + original water. the specific heat of liquid water is 4190 j/kg•k; and the heat of fusion of water is 333 kj/kg. what is the net entropy change of the system from then until the system reaches the final (equilibrium) temperature?