Explain momentum before a collision.

Question

Ball A of mass 5 kilograms moving at 20 meters per second collides with ball B of unknown mass moving at 10 meters per second in the same direction.

 

Which ball has more momentum before the collision?

 

The answer is that they have equal amounts of momentum.

 

But why?? Explain…

Answer 1

The thing is that momentum depends on both mass and velocity. If the two balls have the same momentum,  then the multiplication of the mass and velocity of ball A is equal to the multiplication of mass and velocity for ball B

Example if ball A has mass M(A)= 5kg and has a velocity V(A)=20m/s, then the only way it could have the same amount of momentum with ball B of velocity V(B)=10m/s is for ball B to have a mass M(B)=V(A)×M (A)/V (B)=(20×5)/10=10Kg

Always keep in mind that if the have the same amount of momentum then P(A)=P(B) then M(A)×V(A)=M(B)×V(B)

I hope that helped