chapter ROTATIONAL KINEMATICS Section 8.1 Rotational Motion and Angular Displacement Section 8.2 Angular Velocity and Angular Acceleration 1. Complete the following statement: The angular measure 1.0 radian is equal to (a) 0.0175. (c) 1.57. (e) 6.28. (b) 57.3. (d) 3.14. 2. A bicycle travels 141 m along a circular track of radius 15 m. What is the angular displacement in radians of the bicycle from its starting position? (a) 1.0 rad (c) 3.0 rad (e) 9.4 rad (b) 1.5 rad (d) 4.7 rad 3. What is the angular speed in rad/s of the second hand of a watch? (a) 1.7 x 10-3 rad/s (c) 0.02 rad/s (e) 60 rad/s (b) 0.10 rad/s (d) 6.28 rad/s 4. The Earth takes slightly less than one day to complete one rotation about the axis passing through its poles. The actual time is 8.616 x 10# s. Given this information, what is the angular speed of the Earth about its axis? (a) 7.292 x 10 5 rad/s (c) 9.951 x 10 5 rad/s(e) 1.990 x 10 rad/s (b) 2.321 x 10 6 rad/s (d) 6.334 x 10 rad/s 5. A wheel with a 0.10-m radius is rotating at 35 rev/s. It then slows uniformly to 15 rev/s over a 3.0-s interval. What is the angular acceleration of a point on the wheel? (a) -2.0 rev/s c) -6.7 revis (e) -17 revis2 (b) 0.67 rev/s2 (d) 42 rev/s2 Section 8.3 The Equations of Rotational Kinematics Which equation is valid only when the angular measure is expressed in radians? (a) a = At (c) @ =05+2a0 (e) 0 = 201 + wot (b) w= - At (d) =r 7. During the spin-dry cycle of a washing machine, the motor slows from 95 rad/s to 30 rad/s while the turning the drum through an angle of 402 radians. What is the magnitude of the angular acceleration of the motor? (a) 64 rad/s2 (c) 10 rad/s2 (e) 1.0 rad/s2 (b) 32 rad/s2 (d) 20 rad/s2 8. A fan rotating with an initial angular velocity of 1000 rev/min is switched off. In 2 seconds, the angular velocity decreases to 200 rev/min. Assuming the angular acceleration is constant, how many revolutions does the blade undergo during this time? (a) 10 (c) 100 (e) 1200 (b) 20 (d) 125