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 :

• A. $T$
• B. $T-\frac{m{v}^2}{l}$
• C. $T+\frac{m{v}^2}{l}$
• D. $0$

Answer 1

The correct option is A $T$

When a particle connected to a string revolves in a circular path around a center, 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.,
$F=T=\frac{m{v}^2}{l}$
Where $F$ is the net force acting on the particle.