System Open or Closed#

Two cars collide on a track. Car A comes up behind car B and runs into it. Car A has mass of kg, car B has mass of kg. The following graph shows the velocity of each car as a function of time.

A velocity versus time graph where {{ params_vars_vehicle }} A has an initial velocity of 8 meters per second and {{ params_vars_vehicle }} B has an initial velocity of 1 meter per second. The two {{ params_vars_vehicle }}s collide at around 4 seconds. The velocity of {{ params_vars_vehicle }} A decreases to 2 meters per second and the velocity of {{ params_vars_vehicle }} B increases to 5 meters per second.

Question Text#

Is the system isolated? Why or why not?

Answer Section#

  • Yes, because the two carts are on a track with no friction.

  • Yes, because their change in velocities are the same.

  • No, because the total momentum is nonzero.

  • No, because the momentum is not conserved


Problem is licensed under the CC-BY-NC-SA 4.0 license.
The Creative Commons 4.0 license requiring attribution-BY, non-commercial-NC, and share-alike-SA license.