A uniform force of `(3hati+hatj)` N acts on a particle of mass 2kg. Hence, the particle is displaced from position `(2hati+hatk)`m to position `(4hati+3hatj-hatk)`m. The work done by the force on the particle is

Options

A. 6J
B. 13J
C. 15J
D. 9J

Answer

D

Explanation

Given :`vecF=3hati+hatj`
`vecr_(1)=(2hati+hatK),vecr_(2)=(4hati+3hatj-hatk)`
`vecr=vecr_(2)-vecr_(1)=(4hati+3hatj-veck)-(2hati+hatk)`
or `vecr=2hati+3hatj-2hatk`
So work done by the given force w=`vecF.vecr`
`=(3hati+hatj).(2hati+3hatj-2hatk)`=6+3=9J