A stone lying at rest in a river The minimum mass of stone, `m = krhov^(x) g^(-3)` is needed for remaining at rest here, `h =` constant having no unit , `g =` acceleration due to gravity , `v =` river flor velocity , `rho =` density of water. The value of x is

Options

A. `3`
B. `5`
C. `6`
D. `8`

Answer

c

Explanation

The unit of LHS is `kg` The unit of RHS should be `kg`
Here `krhov^(2)g^(-3)= ((kg)/(m^(3))) ((m)/(s))^(x)((m)/(s^(2)))^(-3)`
`= (kg) (m)^(-3+x - 3)(s)^(+6-x)`
`:. -6 +x = 0`
`rArr x = 6`