A particle of mass `100 g` is thrown vertically upwards with a speed of `5 m//s`. The work done by the force of gravity during the time the particle goes up is

Options

A. `-0.5 J`
B. `-1.25 J`
C. `1.25 J`
D. `0.5 J`

Answer

B

Explanation

`h = (u^(2))/(2g)` , workdone by gravity `= FS cos theta`
here `F = mg, S = h, theta = 180^@`.