Ch 7: Rotational Motion

Question 1

If an object is rotating clockwise, does this correspond to a positive or negative angular velocity?

Answer 1

Negative

Question 2

Likewise, rotation in the counter clockwise direction is the ________ direction.

Answer 2

positive

Question 3

The angular displacement of a rotating object is measured in _______.

Answer 3

radians

Question 4

Moment of inertia is

A. The rotational equivalent of mass.
B. The time at which inertia occurs.
C. The point at which all forces appear to act.
D. An alternative term for moment arm.

Answer 4

A. The rotational equivalent of mass.

Question 5

Which factor does the torque on an object not depend on?
A. The magnitude of the applied force
B. The object’s angular velocity
C. The angle at which the force is applied
D. The distance from the axis to the point at which the force is applied

Answer 5

B. The object’s angular velocity

Question 6

A net torque applied to an object causes

A. A linear acceleration of the object.
B. The object to rotate at a constant rate.
C. The angular velocity of the object to change.
D. The moment of inertia of the object to change.

Answer 6

C. The angular velocity of the object to change.

Question 7

Torque is the _________ _________ of force.

Answer 7

rotational equivalent

Question 8

The formula for calculating torque is:

The component of the force that is _________ to the radial line causes a torque. The parallel component does NOT contribute to torque.

Answer 8

τ = rF sinθ

perpendicular

Question 9

The angular velocity is given by what equation?

Question 10

Graphically, the angular velocity is the ….

Answer 10

….slope of the angular positive-vs-time graph, just as the ordinary velocity is the slope of the position-vs-time graph.

Question 11

What is the formula which relates net torque to the moment of intertia?

Answer 11

τ_net = α I

α is the angular acceleration