The discussion centers on a momentum conservation problem involving two runners colliding and coming to a complete stop. The first runner has a mass of 168 kg and travels north at 5 meters per second, while the second runner's mass is to be determined. The key conclusion is that for the total momentum to be zero after the collision, both runners must have equal mass, which is confirmed to be 168 kg, as they travel at equal speeds in opposite directions.
PREREQUISITESThis discussion is beneficial for physics students, educators, and anyone interested in understanding the principles of momentum conservation in collision scenarios.
sean-820 said:I think that's right. If one was 200lbs then that one would blow through the other guy and not stop at the point of collision like i think the question is saying.
Right.javas1 said:Yes, it is momentum, I believe.
They may or may not bounce off, but no matter what, momentum will be conserved. Here you are told that they come to a stop, so you know they don't bounce off.I read that if two objects crash into each other, then they bounce off each other - and that is not a complete stop.
Yes, exactly right. Since they come to a complete stop, you know that the total momentum is zero. That can only be true if their initial momenta are equal and opposite. Since they have the same speed, the only way they can have the same momentum is if they have the same mass.However, it seems that the mass of both objects would need to be equal, as long as the velocity is equal.
Is that right?
Doc Al said:Right.
They may or may not bounce off, but no matter what, momentum will be conserved. Here you are told that they come to a stop, so you know they don't bounce off.
Yes, exactly right. Since they come to a complete stop, you know that the total momentum is zero. That can only be true if their initial momenta are equal and opposite. Since they have the same speed, the only way they can have the same momentum is if they have the same mass.