A ceiling fan is turned on and reaches an angular speed of 120 rev/min in 20.0 s. It is then turned off and coasts to a stop in 40.0 s. In the 60.0 s of rotation, through how many revolutions did the fan turn?
a. 251
b. 377
c. 126
d. 188
[Ques. 2] A fan blade, initially at rest, rotates with a constant acceleration of 0.025 rad/s2 . What is the time interval required for it to reach a 6.50-rad displacement after starting from rest?
a. 3.61 s
b. 260 s
c. 0.163 s
d. 22.8 s
[Ques. 3] A fan blade, initially at rest, rotates with a constant acceleration of 0.025 rad/s2 . What is its angular speed at the instant it goes through an angular displacement of 7.00 rad?
a. 280 rad/s
b. 0.175 rad/s
c. 0.592 rad/s
d. 880 rad/s
[Ques. 4] A Ferris wheel starts from rest and builds up to a final angular speed of 1.9 rad/s while rotating through an angular displacement of 4.9 rad. What is its average angular acceleration?
a. 9.3 rad/s2
b. 0.37 rad/s2
c. 2.6 rad/s2
d. 0.39 rad/s2
[Ques. 5] Suppose a car has a 100 000-mile 10-year warranty on its wheels and axles. How may turns will the wheels of 0.70-m diameter make if both the mileage and time warranties run out simultaneously and what will be the average angular velocities of the wheel? Assume that a mile = 1.6 103 m and that a year is 3.16 107 s.
a. 7.3E+7, 14 rad/s b. 2.3E+8, 1.4 rad/s
c. 3.5E+8, 1.4 rad/s d. 7.3E+7, 1.4 rad/s
e. 2.3E+8, 14 rad/s
[Ques. 6] Which of the first units given below can be units for angular acceleration while the second units can be units for angular velocity?
a. rev/min2, m/s b. deg/hour, rev/minute
c. rad/s2, deg/hour d. rad/s, rad/s2
[Ques. 7] A 0.12-m-radius grinding wheel takes 6.0 s to speed up from 2.0 rad/s to 11.0 rad/s. What is the wheel's average angular acceleration?
a. 5.6 rad/s2
b. 0.22 rad/s2
c. 1.5 rad/s2
d. 0.080 rad/s2
[Ques. 8] A grindstone spinning at the rate of 8.3 rev/s has what approximate angular speed?
a. 3.2 rad/s
b. 26 rad/s
c. 52 rad/s
d. 81 rad/s
[Ques. 9] 2 600 rev/min is equivalent to which of the following?
a. 2 600 rad/s
b. 43.3 rad/s
c. 272 rad/s
d. 60.0 rad/s
[Ques. 10] An automobile accelerates from zero to 36.72 m/s in 6.80 s. The wheels have a diameter of 0.450 m. What is the average angular acceleration of each wheel?
a. 12.0 rad/s2 b. 24.0 rad/s2
c. 33.6 rad/s2 d. 21.9 rad/s2
e. 18.0 rad/s2
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