Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa

A thin circular ring of mass m and radius R is rotating   about its axis with a constant angular velocity  \omega  .Two objects each of mass    M  are attached gently to the opposite ends of a diameter of the ring. The ring now rotates with an angular velocity \omega {}'  =

Option 1)

\frac{\omega m}{m+2M}

 Option 2)

\frac{\omega \left ( m+2M \right )}{m}
Option 3)

\frac{\omega \left ( m-2M \right )}{\left ( m+2M \right )}

 Option 4)

\frac{\omega m}{\left ( m+M \right )}

Answers (1)

best_answer

As we learnt in

Law of conservation of angular moment -

\vec{\tau }= \frac{\vec{dL}}

- wherein

If net torque is zero

i.e. \frac{\vec{dL}}= 0

\vec{L}= constant

angular momentum is conserved only when external torque is zero .

 

 From conservation of Angular Momentum 

L_{1}=L_{2}

I_{1}\omega_{1}=I_{2}\omega_{2}    \left \lfloor \because\ \;\omega_{1}=\omega, \;\omega_{2}=\omega^{'} \right \rfloor

mR^{2}\omega=\left ( m+2M \right )R^{2}\omega{'} \; \Rightarrow\ \; \omega{'}=\frac{m\omega}{m+2M}


Option 1)

\frac{\omega m}{m+2M}

This is the correct option.

Option 2)

\frac{\omega \left ( m+2M \right )}{m}

This is an incorrect option.

Option 3)

\frac{\omega \left ( m-2M \right )}{\left ( m+2M \right )}

This is an incorrect option.

Option 4)

\frac{\omega m}{\left ( m+M \right )}

This is an incorrect option.

Posted by

Aadil

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

BTech aspirant from north-east or UT? Apply for CSAB NEUT counselling 2025 today
anam-khan

JoSAA round 2 cut-off 2025 out; BTech closing ranks for top engineering courses at IITs
anam-khan

Goa Engineering Admission 2025: 1,415 eligible for BE seats; merit list on June 27

Latest Question