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 • m/s What must the total momentum of the system be after the train cars collide? kg • m/s.

Astudent pushes on a 20.0 kg box with a force of 50 n at an angle of 30° below the horizontal. the box accelerates at a rate of 0.5 m/s2 across a horizontal floor. what is the value of the normal force on the box? 200 n 243 n 156 n 225 n

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

If a star is moving toward earth, it is