Mechanics Conceptual Practice

At a given time, an object is experiencing one force. What can be concluded? (Select all that apply.)

• The object is experiencing a net force.

• The object is in equilibrium.

• The object is moving.

• The object's velocity is changing.

• The object is accelerating.

At a given time, an object is sliding up a frictionless inclined plane. What can be concluded? (Select all that apply.)

• The object is slowing down at that time.

• The magnitude of the normal force on the object is equal to the magnitude of the object's weight.

• The magnitude of the net force on the object is equal to the magnitude of the object's weight.

• The magnitude of the normal force on the object is less than the magnitude of the object's weight.

• The magnitude of the net force on the object is less than the magnitude of the object's weight.

Which of the following is a contact force? (Select all that apply.)

• Normal force

• Weight

• Spring force

• Tension

• Friction

Which of the following expressions givens units of m/s²? (Select all that apply.)

• F / m

• mv² / 2

• v² / (2h)

• Fvt

• 2y / t²

An object is on an elevator that accelerates downward. What can be concluded? (Select all that apply.)

• The magnitude of the normal force on the object is less than the magnitude of the object's weight.

• The magnitude of the normal force on the object is more than the magnitude of the object's weight.

• The magnitude of the normal force on the object is equal to the magnitude of the object's weight.

• The normal force on the object and the force of gravity on the object comprise an action-reaction pair.

• The normal force on the object and the force of gravity on the object are equal in magnitude and opposite in direction.

A rope is attached to an object and used to lift the object directly upward at constant speed? What can be concluded? (Select all that apply.)

• The object is in equilibrium.

• The magnitude of the rope's tension is greater than the magnitude of the object's weight.

• The magnitude of the rope's tension is less than the magnitude of the object's weight.

• The magnitude of the rope's tension is equal to the magnitude of the object's weight.

• The force of tension on the object and the force of gravity on the object comprise an action-reaction pair.

An object is pushed on a flat surface so that it speeds up. Which of the following applies? (Select all that apply.)

• Newton's first law in the y direction

• Newton's first law in the x direction

• Newton's second law in the y direction

• Newton's second law in the x direction

• Uniformly accelerated motion

An object is thrown across a room? (Select all that apply.)

• Newton's first law in the y direction

• Newton's first law in the x direction

• Newton's second law in the y direction

• Newton's second law in the x direction

• Free fall

An object is released from rest on a frictionless inclined plane? (Select all that apply.)

• Newton's first law in the (tilted) y direction

• Newton's first law in the (tilted) x direction

• Newton's second law in the (tilted) y direction

• Newton's second law in the (tilted) x direction

• Uniform motion

An object moving to the left slows down, comes to rest, then speeds up as it moves to the right. What can be concluded? (Select all that apply.)

• The object experiences a net force to the right.

• The object experiences only one force.

• The object accelerates to the right.

• The object is in equilibrium at the moment when it comes to rest.

• Newton's second law applies in the x direction.