Exam 7: Kinetic Energy and Work

A crate moves 10 m to the right on a horizontal surface as a woman pulls on it with a 10-N force. Rank the situations shown below according to the work done by her force, least to greatest.

A particle starts from rest and is acted on by a net force that does work at a rate that is proportional to the time t. The speed of the particle is proportional to:

An 80-N crate slides with constant speed a distance of 5.0 m downward along a rough slope that makes an angle of 30 $\degree$ with the horizontal. The work done by the force of gravity is:

At time t = 0 a particle starts moving along the x axis. If its kinetic energy increases uniformly with t the net force acting on it must be:

An ideal spring is hung vertically from the ceiling. When a 2.0-kg mass hangs at rest from it, the spring is extended 6.0 cm from its relaxed length. A downward external force is now applied to the mass to extend the spring an additional 10 cm. While the spring is being extended by the force, the work done by the spring is:

A 1-kg block is lifted vertically 1 m at constant speed by a boy. The work done by the boy is about:

Three identical springs (X, Y, Z) are arranged as shown. When a 4.0-kg mass is hung on X, the mass descends 3.0 cm. When a 6.0-kg mass is hung on Y, the mass descends:

The weight of an object on the moon is one-sixth of its weight on the Earth. The ratio of the kinetic energy of a body on the Earth moving with speed V to that of the same body moving with speed V on the moon is:

Two objects with masses, m₁ and m₂, have the same kinetic energy and are both moving to the right. The same constant force is applied to the left to both masses. If m₁ = 4m₂, the ratio of the stopping distance of m₁ to that of m₂ is:

In the plot shown of force vs. distance, approximately how much work is done in moving an object from x = 5 m to x = 15 m?

Which of the following is NOT a correct unit for work?

The amount of work required to stop a moving object is equal to the:

In raising an object to a given height by means of an inclined plane, as compared with raising the object vertically, there is a reduction in: