One end of a string of length \(l\) as connected to a particle of mass \(m\) and the other to a small peg on…

One end of a string of length \(l\) as connected to a particle of mass \(m\) and the other to a small peg on a smooth horizontal table. If the particle moves in a circle with speed \(v\) and \(T\) is the tension in the string, then net force on the particle (directed towards the centre) is
  1. \(T\)
  2. 0
  3. \(\frac{T+m v^2}{1}\)
  4. \(\frac{T-m v^2}{I}\)

Solution

The given situation is shown in the following figure
Here, \(N=m g \text { and } T=\frac{m v^2}{l}\) Tension in the string provides necessary centripetal force. Hence, net force on the particle towards centre of circular path is equal to \(T\).

Asked in: AP EAMCET 2020 (17 Sep Shift 2)

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