A vector `vecA` makes an angle of `20^@ and vecB` makes an angle of `110^@` with the X-axis. The magnitude of these vectors are 3 m and 4 m respectively.Find the resultant

Answer

A, C

Explanation

As shown in the figure Angle between `vecA and vecB=110^0-20^0=90^0`
`|vecA|=3m` and `|vecB=4m`
` Resultant, R=sqrt(A^2+B^2+2ABcostheta)`
`sqrt(3^2+4^2+23.4 cos 90^0)`
=5m,

Let `beta` the angel between `vecR and vecA beta=tan^-1((4sin 90^0)/(3+4 cos 90^0))`
`=tan^-1 4/3`
`=tan^-1 (1.333), =53^0`
Resultant vector makes angle,` 53^0+20^0`
` =73^0` with x-axis.