Question

One end of a string of length l is 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 the net force on the particle (directed towards the centre) is:

(i) T, (ii) T-(mv²)/l (iii) T+(mv²)/l (iv) 0

T is the tension in the string. [Choose the correct alternative].

Answer 1

(i) T
When a particle connected to a string revolves in a circular path around acentre, the centripetal force is provided by the tension produced in the string. Hence, in the given case, the net force on the particle is the tension T, i.e.,
= =(mv²)/l

Where F is the net force acting on the particle.