  # Circular Motion - L1

Physics

## example

### Objects moving in vertical circle with tension as the centripetal force

Example: A mass of tied to a string of length is rotating in a vertical circle with a uniform speed of .Find the position of mass  when tension in the string will be .[Take ]

Solution:
( is the angle from the horizontal line
Thus we get:
Thus
Thus the tension of 52 N would occur at the bottom most point.

## example

### Objects in vertical circle with normal reaction as centripetal force

Example: A block is freely sliding down from a vertical height on a smooth inclined plane. The block reaches bottom of inclined plane then it describes vertical circle of radius along smooth track. What is the ratio of normal reactions on the block while it is crossing lowest point and highest point of vertical circle is:

Solution:
Applying the law of conservation of energy at point A and B, we have

Now, net force is towards the center is the centripetal force, we have at point B

..........
applying the law of conservation of energy at point B and C, we have

Now, net force is towards the center is the centripetal force, we have at point C

..........
So the ratio of normal reactions on the block while it is crossing lowest point, highest point of vertical circle is:
..from and