Non Uniform Vertical Circular Motion

One end of the string of length is connected to a particle of mass and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in a circle with speed , the net force on the particle (directed towards the center) will be: ( represents the tension in the string)

1.		2.
3.	zero	4.

A point mass is moved in a vertical circle of radius with the help of a string. The velocity of the mass is at the lowest point. The tension in the string at the lowest point is:

1.		2.
3.		4.

A bob of heavy mass is suspended by a light string of length The bob is given a horizontal velocity as shown in figure. If the string gets slack at some point making an angle from the horizontal, the ratio of the speed of the bob at point to its initial speed is: 

1.		2.
3.		4.