When Freddy Frog drops vertically from a tree onto a horizontally-moving skateboard, he doesn’t slip off the skateboard because of

If the mass of an object does not change, a constant net force on the object produces constant

A 1-kg glider and a 2-kg glider both slide toward each other at 1 m/s on an air track. When they collide and stick, the combined-glider speed is

When a 100-kg astronaut ejects 0.1 kg of gas at a speed of 50 m/s from her propulsion pistol, her recoil speed is

The amount of gravitational force that acts on a space vehicle that orbits Earth is

A 0.5-kg blob of clay moving at 2.0 m/s slams into a 4.0-kg blob of clay at rest. The speed of the two blobs stuck together after colliding is about

Lillian pulls on a 10-kg wagon with a constant force of 30 N. What is the wagon’s acceleration?

A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball initially at rest. After the putty sticks to the ball, both move with a combined momentum of

A girl pushes a cart to the left with a 100-N force. At the same time a boy pushes it to the right with a 50-N force. The net force exerted on the cart is

A stone is thrown horizontally from the top of a cliff. One second after leaving your hand it drops a vertical distance of