Question

A merry-go-round, made of a ring-like platform of radius R and mass M. is revolving with angular speed $\omega$? A person of mass M is standing on it. At one instant., the person jumps off the
round, radially away from the center of the round (as seen from the round). The speed of the round afterwards is:

• A. $2\omega$
• B. $\omega$
• C. $\frac{\omega }{2}$
• D. 0

Answer 1

The correct option is A $2\omega$

Here angular momentum is converted

$L_i=L_f$

$(I_{ring}+M{R}^2)\omega =(L_{man}+L_{ring}){\omega }^{\prime }$ $L_{man}=L_{ring}$

[A man is assumed to at circumstances of ring and is final angular speed of ring after men jump off]

$(M{R}^2+M{R}^2)\omega =O+M{R}^2{\omega }^{\prime }$

$2\omega ={\omega }^{\prime }$

Hance (A) option is correct