Question

A small coin of mass m1 is undergoing a uniform circular motion at a velocity v. The radius of the circular path is r. A piece of putty of mass m2 is dropped onto the coin. The new velocity of the coin-putty system is _____.

A. vB. m1v/m2C. m2v/m1D. m1v/(m1 +m2)E. m2v/(m1 +m2)

Answer 1

Answer:

Answere is (D)

Explanation:

Given m1, v and m2

Total circular momentum is conserved: total circular momentum before putty coin collision is equal to total circular momentum after collision.

Let the final circular velocity of the system be V. Initial circular velocity of the putty is zero.

m1v + m2× 0 = (m1 + m2) V

V = m1v/(m1 + m2).