A large truck breaks down out on the road and receives a push back to town by a small compact car.

Pick one of the choices A through F below which correctly describes the forces that the car exerts on the truck and the truck exerts on the car for each of the questions. You may use an answer more than once or not at all.

A. The force exerted by the car pushing against the truck is equal to that exerted by the truck pushing back against the car.

B. The force exerted by the car pushing against the truck is less than that exerted by the truck pushing back against the car.

C. The force exerted by the car pushing against the truck is greater than that exerted by the truck pushing back against the car.

D. The car's engine is running so it exerts a force as it pushes against the truck, but the truck's engine isn't running so it can't exert a force back against the car.

E. Neither the car nor the truck exert any force on each other. The truck is pushed forward simply because it is in the way of the car.

F. None of these descriptions is correct.

If the car and truck are moving at cruising speed, which choice(s) below are true?

1. The car is pushing on the truck, but not hard enough to make the truck move.

2. The car, still pushing the truck, is speeding up to get to cruising speed.

3. The car, still pushing the truck, is at cruising speed and continues to travel at the same speed.

4. The car, still pushing the truck, is at cruising speed when the truck puts on its brakes and causes the car to slow.

To examine the final answers, we must silver the solution of the problem, if we see Newton's third law, action and reaction, we see that the car pushes the truck the action, the truck must oppose this force with a force applied on the car of equal magnitude, but opposite direction

In view of the above, let's review the statements.

A True. It agrees with Newton's third law

B False. Violate Newton's third law

C False violate Newton´s third law

D False. The force is exerted by the car not specifically by the engine

E Faults if no force is exerted the truck should stop due to friction

Second question

If the two vehicles move at the same speed, the resulting force on each of them must be zero

1 False. If the truck doesn't get nine, it can't go at cruising speed

2 False if the car is accelerating it cannot go at constant speed

3 True. The car pushes the truck and goes at constant speed

4 False. If the truck slows it should slow down