Question

a mass 1.9kg is suspended from a string of length 0.5m at rest. another body of mass 100gm. moving horizontally strikes the mass and sticks to it. if the combined mass just able to complete the circle, initial velocity of the body is

Answer 1

Minimum velocity to complete a vertical circle is (5gr)^1/2

Let velocity of the body be v and final velocity after sticking be u.

By conservation of momentum,

0.1 x v = (1.9+0.1) u --> u=0.05v

now, u=(5gr)^-1/2 --> 0.05v=(25)^1/2 ---> v=5/0.05 ---> v=100m/s

Answer 2

Explanation:

a mass 1.9kg is suspended from a string of length 0.5m at rest. another body of mass 100gm. moving horizontally strikes the mass and sticks to it. if the combined mass just able to complete the circle, initial velocity of the body is