1. The problem statement, all variables and given/known data An engine provides a constant force F to a car of mass M that carries a box of mass m on the top of it. After traveling from rest with constant acceleration a1 for 20 seconds, the speed of the car becomes 40m/s and at that instant the box falls off the car. In the next 20 seconds, with force F remaining constant, the car travels with constant acceleration, a2, 1280 meters from the point the box fell. The ratio of the accelerations a2/a1 would be: I got 1.2, which is correct. The ratio m/M would be: The answer is (a2-a1)/a1, I just don't know how to get there. 2. Relevant equations F=MA 3. The attempt at a solution I have a feeling this is simple, but I can't seem to work it out.