Two train cars with the same mass (30,000 kg) are traveling in the same direction when they collide. Train Car A has a velocity of 10 m/s and Train Car B has a velocity of 5 m/s. What is their total
momentum after the collision? Make sure to show all your work and include proper units.

On a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 3.00 m/s.(a) what are the magnitude and direction of the velocity of the red glider after the collision? (b) is this collision elastic?