1. The problem statement, all variables and given/known data A 1000 kg plane is trying to make a forced landing on the deck of a 2000 kg barge at rest on the surface of a calm sea. The only frictional force to consider is between the plane’s wheels and the deck; this braking force is constant and is equal to one-quarter of the plane’s weight. What must the minimum length of the barge be for the plane to stop safely on deck, if the plane touches down just at the rear end of the deck with a velocity of 50 m/s toward the front of the barge? 2. Relevant equations F=ma p=mv Kinematic equations. Although I'm not sure where this one will be used... mPvP +mBvB = mPvP'+mBvB' Where ' represent final condition Also possibly KE=KE'------ Not sure if elastic???? 3. The attempt at a solution The frictional force the plane and boat will experience is 2450N (by newtons third law, equal and opposite) Lets set rear of boat to be - and the direction of travel of the plane to be + By F=ma, the plane will accelerate at -2.45m/s2 and the boat will accelerate at 1.225m/s2 Im not sure where to go from here. This is meant to be a momentum question yet I don't see where that would be applicable. Also the question does not specify weather the point at which the plane collides with the boat is elastic or inelastic.