(Multiple choice)

(1)

The angular momentum vector for a spinning wheel lies along its axle and is pointed east. To make this vector point south, it is necessary to exert a force on the east end of the axle in which direction? 

(a) Up 

(b) Down 

(c) North 

(d) South 

(e) East

(2)

A man is walking north carrying a suitcase that contains a spinning gyroscope mounted on an axle attached to the front and back of the case. The angular velocity of the gyroscope points north. The man now begins to turn to walk east. As a result, the front end of the suitcase will 

(a) Resist his attempt to t urn and will try to remain pointed north. 

(b) Fight his attempt to turn and will pull to the west. 

(c) Rise upward. 

(d) Dip downward. 

(e) Cause no effect whatsoever.

(3)

An object of mass M is rotating about a fixed axis with angular momentum L. Its moment of inertia about this axis is I. What is its kinetic energy? 

(a) IL²/2 

(b) L² /2I 

(c) ML²/2 

(d) IL²/2M

(4)

A woman sits on a spinning piano stool with her arms folded. When she extends her arms out to the side, her kinetic energy 

(a) Increases. 

(b) Decreases. 

(c) Remains the same.

(5)

In tetherball, a ball is attached to a string that is attached to a pole. When the ball is hit, the string wraps around the pole and the ball spirals inward. Neglecting air resistance, what happens as the ball swings around the pole? Give supporting arguments for y our choice. 

(a) The mechanical energy and angular momentum of the ball are conserved. 

(b) The angular momentum of the ball is conserved, but the mechanical energy of the ball increases. 

(c) The angular momentum of the ball is conserved, and the mechanical energy of the ball decreases. 

(d) The mechanical energy of the ball is conserved and the angular momentum of the ball increases. 

(e) The mechanical energy of the ball is conserved and the angular momentum of the ball decreases.