2nd Nine-Weeks
Week # 06
Physics
CW 02: Circular Motion
Name: ____________________________________________ Date: __________ Period: ________
You must show the work that leads to your answer to receive credit. The answer must include the
appropriate unit.
_______________________1. Convert 3000 rpm (revolutions per minute) to radians/sec.
[314 rad/sec]
_______________________ 2. Convert 5 rotations into radians. [31.4 rad]
_______________________ 3. Convert 250 radians/sec to rpm (revolutions per minute).
[2389 rpm]
_______________________ 4. What is the rotational inertia of a bicycle wheel that is 1.5 kg and
60 cm in diameter? [0.135 kg m2]
_______________________ 5. What is the rotational inertia of a baseball with a mass of
0.3 kg and 8 cm in diameter? [0.000192 kg m2]
6. A car’s tires are 0.70 m in diameter. They spin at 200 rpm. How fast is the car moving?
_______________________ (a) Convert rpm to rad/sec [20.9 rad/sec]
_______________________ (b) How fast is the car moving? [7.33 m/sec]
_______________________ 7. A bicycle is moving at 12 m/s. The tires are 0.80 m in diameter.
How many rpm are the tires spinning? [287 rpm]
8. A 4 kg disc has a diameter of 0.50 m. A force of 4 N is applied to the rim for 12 seconds. The disc
starts from rest. What rotational speed (in rpm) does it attain?
_______________________(a) Calculate the inertia of the disc. [0.125 kg m2]
_______________________ (b) Calculate acceleration. [8 rad/sec2]
_______________________(c) Calculate velocity [96 rad/sec]
_______________________ (d) Convert the velocity from rad/sec to rpm (rev/min) [
rpm]