The resultant of two forces, one double the other in magnitude, is perpendicular to the smaller of the two forces, the angle between the two forces is

Options

A. `120^(@)`
B. `60^(@)`
C. `90^(@)`
D. `150^(@)`

Answer

A

Explanation

`vecR` is the resultant of `vecP` and `2vecP` is perpendicular to the vector `vecP`.
Let `theta` be the angle between the two vectors `vecP and 2vecP`
Then `tan90^(@)=(2Psintheta)/(P+2Pcostheta)`
`thereforeP+2Pcostheta=0`
`impliescostheta=-1//2thereforetheta=120^(@)`