Q.

A particle starting from rest, moves in a circle of radius 'r'. It attains a velocity of V0 m/s in the nth round. Its angular acceleration will be          [2019]
 

1 V0nrad/s2  
2 V02πnr2rad/s2  
3 V024πnr2rad/s2  
4 V024πnrrad/s2  

Ans.

(3)

Distance travelled in nth rounds =(2πr)n

Using v2=u2+2as or, V02=0+2a(2πr)na=V024πnr

Angular acceleration, α=ar=V024πnr2rad/s2