A model rocket flies straight upward with constant acceleration, undergoing a displacement of 15.0 m during its first 0.25 s of travel. What was its speed at the end of the first 0.25 s, assuming it started from rest

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer

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 •  

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up