Practice Problems 2 Circular Motion PDF

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practice problems Practice Problems 2 Circular Motion...

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Practice Problems #3 Circular/Rotational Motion and Graphs of Motion Physics NYA - Chris Tromp 1. A vinyl record of diameter 12 inches (you are not expected to know what an inch is for the test, but you are expected to find out for this problem.) is spinning at 33 rpm and then the machine is turned off, causing it to slow down at a constant rate, coming to a stop in 5.0 seconds. Determine: a) the angular acceleration. [-0.691 rad/s2] b) the tangential acceleration of a point on the edge of the record. [-0.105 m/s2] c) the tangential velocity of a point on the edge 3.0 seconds before it stops. [0.317 m/s] d) the total angle (in radians) through which it turns as it stops. [8.64 rad] e) the number of revolutions through which it turns as it stops. [1.37 rev] 2. A pulley of radius 8.2 cm is attached to an electric motor. A belt around the pulley is also wrapped around another pulley of radius 18.7 cm. When the motor is turned on, it accelerates at a constant rate of 30 rad/s2. a) What is the angular acceleration of the larger pulley? [13.2 rad/s2] b) What is the linear speed of the belt after 6.2 seconds? 3. The graph at right shows the angular velocity of a disk as a function of time. Determine: a) the angular acceleration of the disk. [-2 rad/s2] b) the number of rotations of the disk during the first 10 seconds [15.9 rotations] c) The total angular displacement of the disk during the full 15 seconds. [75 radians]

[15.3 m/s] ω (rad/s)

20 10 t (s) 0

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4. A car travelling at a constant speed 60 km/h goes around a curve of radius 75 m. What is its acceleration? [3.70 m/s2]

5. A centrifuge is a device which spins materials at very high rotational speeds. What is the acceleration of a material spinning in a centrifuge at a rate of 10 000 rpm at a radius of 10 cm? Express your answer as a multiple of the gravitational acceleration g = 9.81 m/s2. [11200g] 6. What is the total acceleration of a car which is currently travelling at 50 km/h at the start of a curve of radius 62 m but is speeding up at a constant rate so that it will have reached a speed of 80 km/h after completing the 90° turn? Note: you are asked for the total acceleration at the start, when it is going 50 km/h but speeding up. [3.47 m/s2, 63.6° to the tangential direction]...