A driver who is moving at 15 m/s, sees a stop light and puts on the brakes 30 m before an intersection. a) What acceleration will the driver have to have to stop before entering the intersection?

b) How much time will it take to stop the car?

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 •  

Arigid tank is divided into two equal parts by a partition. one part of the tank contains 3 kg of compressed liquid water at 400 kpa and 60°c while the other part is evacuated. the partition is now removed, and the water expands to fill the entire tank. determine the entropy change of water during this process, if the final pressure in the tank is 40 kpa. use steam tables.

Ryan is examining the energy of the particles in a bar of gold. what is ryan most likely studying?