A2L Item 175

Goal: Problem solving

Source: UMPERG-ctqpe135.1

disk, having radius R and mass M, is free to rotate about an axis
through its center. A massless string is wound around disk and attached
to mass m. The moment of inertia for a disk given by is
1/2(MR2). If M=4m what is the acceleration of mass m?

  1. 0
  2. g/2
  3. g/8
  4. g/5
  5. g/3
  6. None of the above
  7. Cannot be determined



(5) Students answering #2 are likely making the common mistake of
thinking that the tension in the string is mg.