Five substitute players on a basketball team are sitting on the bench during a game. The bench weighs and, altogether, the players weigh . Two players, weighing and , stand up. What is the difference in the normal force acting on the bench before and after these players leave?

A block is placed on a incline. What is the normal force of the incline on the box?

A 2kg box is at the top of a frictionless ramp at an angle of 60o. The top of the ramp is 30m above the ground. The box is sitting still while at the top of the ramp, and is then released.

If the angle of the ramp is decreased, which of the following statements is false?

A woman is standing on a scale in an elevator as it accelerates upward. The elevator then stops accelerating and continues upward at a constant speed. Which of the following statements is true?

A person tries to lift a very heavy rock by applying an upward force of , but is unable to move it upward. Calculate how much additional force was needed to lift the rock from the ground.