Goal: Problem solving with rotational kinematics
Source: UMPERG-ctqpe110
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:
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.