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

Starting point of particle `= hat(i) + 3 hat(k)`
Ending point of particle `= - 3 hat(i) + 4 hat(j) + 5 hat(k)`
Force `(F) = hat(i) + 5 hat(k)`
`:.` Displacement of the particle
`(s) = (- 3 hat(i) + 4 hat(j) + 5 hat(k)) - (hat(i) + 3 hat(k))`
`= - 4 hat(i) + 4 hat(j) + 2 hat(k)` we know that,
work done, W = F.s
or, `W = (hat(i) + 5 hat(k)) - (- 4hat(i) + 4 hat(j) + 2 hat(k))`
or, `W = - 4 + 10` or `W = 6 J`