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 center) is:
1. \(T\)
2. \(T-\frac{m v^2}{l}\)
3. \(T+\frac{m v^2}{l}\)
4. \(0\)
A stone of mass 0.25 kg tied to the end of a string is whirled around in a circle of radius 1.5 m with a speed of 40 rev/min in a horizontal plane. The tension in the string is:
1. 5.6 N
2. 6.6 N
3. 3.4 N
4. 4.2 N