A person aiming to reach the exactly opposite point on the bank of a stream is swimming with a speed of `0.5 ms^-1` at an angle of `120^(@)` with the direction of flow of water. The speed of water in the stream, in `ms^-1` is ,

Options

A. `1:0`
B. `1/sqrt3`
C. 0.25
D. 0.433

Explanation

`|0.5hati+0.8hatj+chatk|=1`
`impliessqrt((0.5)^2+(0.8)^2+c^2)=1`
`implies(0.5)^2+(0.8)^2+c^2=1`
`impliesc^2=0.110`
`:.c=sqrt0.11`