Laws of Motion Rotational Motion

A mass ‘m’ is supported by a massless string wound around a uniform hollow cylinder of mass m and radius R. If the string does not slip on the cylinder, with what acceleration will the mass fall on release?

  1. g
  2. 5g/6
  3. g/2
  4. 2g/3

Answer

For the mass m,

mg - T = ma

For the cylinder,

TR = mR2 a/R

T = ma

mg = 2ma

a = g/2

The correct option is C.