Two boats with masses m and M are tied with a rope. A motor in the small boat pulls the rope with a force F.    What are the accelerations of the boats?

Verify, that each boat`s acceleration can be found using Newton`s second law: ma = F  or  a = F / m. The distance travelled in time t can be found using the formula for motion with a constant acceleration, with zero initial velocity: S = a t2 / 2. Newton`s third law is expressed in the experimental fact that the pulling force F12 exerted by the first boat on the second, is equal to the opposite force F21 : F12 = - F21. The minus sign signifies the opposite direction.

Initial Values of Parameters Mass of a small boat (m) 4 kg Mass of a big boat (M) 7 kg Pulling force (F) 8 N