A car of mass `1000kg` negotiates a banked curve of radius `90m` on a fictionless road. If the banking angle is `45^(@)` the speed of the car is:

Options

A. `20 ms^(-1)`
B. `30 ms^(-1)`
C. `5 ms^(-1)`
D. `10 ms^(-1)`

Answer

B

Explanation

The angle of banking
`tantheta=(v^(2))/(rg)`
Given, `theta=45^(@), r=90n" and "g=10ms^(-2)`
`tan45^(@)=(v^(2))/(90xx10)rArrv=sqrt(90xx10xxtan45^(@))`
Speed of car, `v=30ms^(-1)`