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A mass 2 kg is whirled in a horizontal c...

A mass 2 kg is whirled in a horizontal circle by means of a string at an initial speed of 5 revolutions per minute . Keeping the radius constant the tension in the string is doubled. The new speed is nearly

A

14 rpm

B

10 rpm

C

2.25 rpm

D

7 rpm

Text Solution

Verified by Experts

The correct Answer is:
D
Tension In the string `T=m omegaa ^(2) r=4pi^(2)n^(2)` mr
`therefore T alpha n^(2)implies(n_(2))/(n_(1))=sqrt((T_(2))/(T_(1)))impliesn_(2)=5sqrt((2T)/(T))=7"rpm"`.
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