A2L Item 108
- Description: Determine the time for angular displacement given information about angular acceleration and velocity.
- Goal: Problem solving with rotational kinematics
- Source: UMPERG-ctqpe110
- Keywords: Mechanics, Rotational Motion
The question for students:
A flywheel rotating about an axis through its center starts from rest, rotates with constant angular acceleration for 2 seconds while making one complete revolution and thereafter maintains constant angular velocity. How long does it take the wheel to make a total of 6 full revolutions?
- 4 secs
- 5 secs
- 6 secs
- 7 secs
- 9 secs
- None of above
- Cannot be determined
Commentary for teachers:
Answer
(4) This problem provides an excellent opportunity to discuss the power of graphs for problem solving. Making a sketch of angular velocity vs. time provides the easiest way to answer the problem. Conversely, an algebraic solution is complicated.