66. Consider the use of the terms "rotation" and "revolution". : 2102163
66. Consider the use of the terms "rotation" and "revolution". In physics:
A. the words are used interchangeably.
B. the words are used interchangeably but "rotation" is the preferred word.
C. the words have different meaning.
D. "rotation" is the correct word and "revolution" should not be used.
67. A solid disk of radius R rolls down an incline in time T. The center of the disk is removed up to a radius of R/2. The remaining portion of the disk with its center gone is again rolled down the same incline. The time it takes is:
B. more than T.
C. less than T.
D. requires more information than given in the problem to figure out.
68. The quantity "angular momentum" (in terms of the fundamental quantities of mass, length, and time) is equivalent to:
69. A ventilation fan with a moment of inertia of 0.034 kg?m2 has a net torque of 0.11 N?m applied to it. If it starts from rest, what angular momentum will it have 8.0 s later?
A. 0.88 kg?m2/s
B. 0.97 kg?m2/s
C. 2.0 kg?m2/s
D. 3.25 kg?m2/s
70. A figure skater with arms initially extended starts spinning on the ice at 3 rad/s. She then pulls her arms in close to her body. Which of the following results?
A. a smaller rotational rate
B. a greater rotational rate
C. a greater angular momentum
D. a smaller angular momentum