Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
Home  >>  JEEMAIN and AIPMT  >>  Physics  >>  Class11  >>  Oscillations
0 votes

A disc of mass 'm' and radius 'r' is present on a rough surface . Find the angular frequency (w) of the S.H.M . Consider pure rolling of the disc

$(a)\;\sqrt{\large\frac{8K_{1}}{3m}}\qquad(b)\;\sqrt{\large\frac{4 K_{1}}{3m}}\qquad(c)\;\sqrt{\large\frac{K_{1}}{3m}}\qquad(d)\;None\;of\;these$

Can you answer this question?

1 Answer

0 votes
Answer : (c) $\;\sqrt{\large\frac{K_{1}}{3m}}$
Explanation :
Let the disc roll on the surface and the centre be moved by a distance x .
Therefore , The top most point of the disc will move by a distance of 2x .
Therefore , Considering free body diagram of the systems
$f$= (friction)
$T=2 K_{1}x$
Considering torque about centre
$(T+f)\;r=\large\frac{mr^2}{2} \times \alpha$
As the disc rolls a=$\;r \alpha$
$2T=\large\frac{3ma}{2} \; => T=\large\frac{3ma}{4}$
answered Mar 10, 2014 by yamini.v
edited Mar 10, 2014 by yamini.v

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, NEET Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App