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 :
$(i) \;T,$ $(ii)\; T-\frac{m v^{2}}{l},$ $(iii)\;T+\frac{m v^{2}}{l},$ $(iv) \;0$
$T$ is the tension in the string. [Choose the correct alternative].
$(i)$ $T$ 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 $T$, i.e.,
$F=T=\frac{m v^{2}}{l}$
Where $F$ is the net force acting on the particle.
Which of the following is the correct order of forces
A body of mass $m_1$ exerts a force on another body of mass $m_2$. If the magnitude of acceleration of $m_2$ is $a_2$, then the magnitude of the acceleration of $m_1$ is (considering only two bodies in space)
In the figure shown, $A$ & $B$ are free to move. All the surfaces are smooth. then $(0 < \theta < 90^o)$