A 70 kg person walking around a corner collided with an 80 kg person who was running from the opposite direction. After the collision the two people stayed together. Which of the following is true?


The 70 kg person received the larger impulse

The 80 kg person received the larger impulse

They both had equal, but opposite change in momentum

After the collision their combined speed was zero.


The answer would be they both had an equal, but opposite change in momentum correct?

The answer would be they both had an equal, but opposite change in momentum correct?

Yes indeed. Since impulse equals F \Delta t, and both bodies experienced the same magnitude of force in the collision (equal and opposite reactions) for the same amount of time, they must have both received the same impulse but in opposite directions. Remembering that impulse = change in momentum, they must therefore experience the same magnitude of change in momentum. And since the total momentum of the system must be zero, this means that they both experienced equal and opposite changes in momentum.