A 125 kg wrecking ball on a 15.4 m long cable is pulled back to an angle of 33.5° and released. How much KE does it have at the bottom of its swing?

=force × distance a. work b. velocity c. pressure d. momentum

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 •  

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.