What is one weird thing that happens at absolute zero?

The long handle on a rake is a(n) a. lever b. screw c. wedge d. inclined plane

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

Assume this car is driven off a cliff . how many arrows of force need to be drawn in the free body diagram? assume no air resistance -five -one -three -four