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. $\text T$
• B. $\text T- \frac{mv^2}{l}$
• C. $\text T+ \frac{mv^2}{l}$
• D. 0

Answer 1

Answer: (A)

$\text T$

Answer 2

When a particle connected to a string revolves in a circular path around a centre, 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 $\text T$, i.e.,
$\text F$ = $\text T$ = $\frac{mv^2}{l}$
Where $\text F$ is the net force acting on the particle.

Therefore, the correct option is (a): $\text T$