WPE Review

The magnitude of the work done to a ball by a pitcher is ______________ the magnitude of the work done by the catcher in stopping the ball.  The ball leaves the pitcher’s hand at the same velocity that it arrives at the catcher’s glove.

• greater than

• less than

• equal to

The magnitude of the force done to a ball by a pitcher is ______________ the magnitude of the work done by the catcher in stopping the ball.  The ball leaves the pitcher’s hand at the same velocity that it arrives at the catcher’s glove.

• greater than

• less than

• equal to

A box is pulled horizontally 5.0 m by a 40 N force at an angle of 60° above the horizontal.  What is the work (J) done on the box?

A 2.0 kg ball is dropped from an initial height.  When the ball reaches the ground it has a KE of 16 J.

What is the speed (m/s) of the ball 0.50 above the ground?

A student pulls a block 3.0 meters along a horizontal surface at constant velocity. The diagram shows the components of the force exerted on the block by the student.

How much work (J) is done against friction?

The graph represents the elongation of a spring as a function of the force.

What is the value of the spring constant (N/m)?

The diagram below shows a moving, 5.0 kg cart at the foot of a hill 10 meters high. For the cart to reach the top of the hill, what is the minimum seed (m/s) of the cart in the position shown? [Neglect energy loss due to friction.]

Given the graph shown, what quantity would be represented by the slope?

As shown in the diagram, a student exerts an average force of 600. newtons on a rope to lift a 50 kg crate a vertical distance of 3.0 meters.

How much work (J) is lost to friction during the lift?

A 85 kg student climbs 4.0 meters up a rope in 3.0 seconds. What is the power output (W) of the student?