dynamics question helpWatch
Why is the answer D? How would we use the kinetic energy formula to derive the answeR?
relative speed of approach before collision is equal to the relative speed of separation after collision
Let the left particle be particle A and the right particle be particle B. Let the initial state be denoted with 1 and the final state be denoted with 2.
Consider the conservation of (kinetic) energy:
Consider the conservation of momentum:
Equate the two expressions:
Now, , as particle B is experiencing an impulse from the collision of particle A. Hence, .
Return to the conservation of momentum: