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

Answer

A

Explanation

(a) Given, force `F=3hati+hatj`
`r_(1)=(2hati+hatk)m " and "r_(2)=(4hati+3hatj-hatk)m`
`:. " "s=r_(2)-r_(1)=(4hati+3hatj-hatk)-(2hati+hatk)`
`=(2hati+3hatj-2hatk)m`
`:." " W=F.s=(3hati+hatj).(2hati+3hatj-2hatk)`
`=3xx2+3+0=6+3=9J`