A ball is moving in a circular path of radius 5m. If tangential acceleration at any instant is 10 `m//s^(2)` and the net acceleration makes an angle `30^(@)` with the centripetal acceleration, then the instantaneous speed is

Options

A. `50sqrt(3)m//s`
B. `9.3m//s`
C. `6.6m//s`
D. `5.4m//s`

Answer

B

Explanation

From relation,
`tantheta=(a_(t))/(a_(c))=(a_(t))/(v^(2)//r)`
`impliesv^(2)=(a_(t)r)/(tantheta)`
`=(10xx5)/(tan30^(@))=50sqrt(3)`
`=50xx1.732=86.6`
`thereforev=sqrt(86.6)=9.3m//s`