A0.250 kg toy truck is rolling across the floor at a rate of 1.25 m/s. it is pushed by your sister with a force of 0.5 n over 2.2 s in the same direction of travel. what is its new velocity when she lets go to watch it?

A100 kg running back runs at 5m/s into a stationary linebacker. it takes 0.5 for the running back to be completely stopped

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 •  

In a set amount of time, a battery supplies 25j of energy to an electric circuit that includes two different loads. one of the loads produces 10 j of heat energy during this time interval. how much heat energy is produced by the second load in this time? explain your answer