A body constrained to move in y direction is subjected to a force given by `vec(F)=(-2hat(i)+15hat(j)+6hat(k))` N . What is the work done by this force in moving the body through a distance of `10 m` along y-axis ?

Options

A. 160 J
B. 190 J
C. 150 J
D. 20 J

Answer

C

Explanation

Work done by a force in displacing a body through a distance S is given by
`W = vec F cdot vec S`
`=(-2hati+15 hatj +6hatk) cdot (10hatj)`
Since the displacement along Y axis is given by `10 hatj`
`therefore W =0+150 +0 =150 J`
`[because hati cdot hatj =hatj cdot hatk =hatk cdot hati =0 and hatj cdot hatj =1]`