A2L Item 108

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

  1. 4 secs
  2. 5 secs
  3. 6 secs
  4. 7 secs
  5. 9 secs
  6. None of above
  7. Cannot be determined



(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.