Question

A uniform disc is thrown on a horizontal rough
surface in such a way that it slides with speed vo
intially without angular motion. It will start rolling
without slipping when its speed reduces to
1) v0/2
2)2v0/3
3)3v0/5
4)5v0/7




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Answer 1

Answer:

Correct option is

4

(5/7)V  

0

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Angular momentum conservation will apply here.

Initial angular momentum =mV  

o

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r

Moment of inertia about centre =(2/5)mr  

2

 

Let final velocity be V.

There final momentum =I(V/r)+mVr

Therefore, mV  

o

​

r=(2/5)mVr+mVr

V=5/7V  

o

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Answer 2

Explanation:

A uniform disc is thrown on a horizontal rough

surface in such a way that it slides with speed vo

intially without angular motion. It will start rolling

without slipping when its speed reduces to

1) v0/2

2)2v0/3

3)3v0/5

4)5v0/7