Two students, standing on skateboards, are initially at rest, when they give each other a shove! After the shove, one student (78kg) moves to the left at 6.1m/s while the other student (57kg) moves right.

Acar travels along a highway with a velocity of 24 m/s, west. the car exits the highway; and 4.0 s later, its instantaneous velocity is 16 m/s, 45° north of west. what is the magnitude of the average acceleration of the car during the four-second interval?

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity

If you put a helium-filled balloon in the refrigerator, what will happen?