When the angular velocity of a uniformly rotating body has increased thrice the resultant of forces applied to it increases by 60 N. Find the acceleration of the body in two cases, if the mass of the body is 3 kg:

Options

A. `2.5ms^(-2),7.5ms^(-2)`
B. `7.5ms^(-2),22.5ms^(-2)`
C. `5ms^(-2),45ms^(-2)`
D. `2.5ms^(-2),22.5ms^(-2)`

Answer

D

Explanation

`F=mromega_(0)^(2)`,`F_(2)=mr(3omega_(0))^(2)`
`F_(2)-F_(1)=9mromega_(0)^(2)-mromega_(0)^(2)=3mromega_(0)^(2)`
`60=8xx3(romega_(0)^(2))`or `romega_(0)^(2)=(60)/(24)=(5)/(2)`
Now `a_(1)=romega_(0)^(2)=2.5ms^(-2)`
`a_(2)=9romega_(0)^(2)=9xx(5)/(2)=22.5m^(-2)`