A particle moves from (1,0,3) to the point (-3,4,5) when a force `F = hat(i) + 5 hat(k)` acts on it. Amount of work done in joules is

Options

A. 14
B. 10
C. 6
D. 15

Answer

C

Explanation

Particle's starting point `=(hat(i)+3hat(k))`
Particle's ending point `=3hat(i)+4hat(j)+5hat(k)`
Force (F)`=hat(i)+5hat(k)`
Displacement `=(-3hat(i)+4hat(j)+5hat(k))-(hat(i)+3hat(k))`
`=-4hat(i)+4hat(j)+2hat(k)`
Work done =Force x displacement
`=(hat(i)+5hat(k))(-4hat(i)+4hat(j)+2hat(k))`
`=-4+10`
`=6J` .