Calculate the work done by a student in lifting a 0.5 kg book from the ground and keeping it on a shelf of 1.5 m height. (g = 9.8 `m//s^(2)`)

Explanation

The mass of the book = 0.5 kg
The force of gravity acting on the book is equal to 'mg'
That is mg = 0.5 `times` 9.8 = 4.9 N
The students has to apply a force equal to that of force of gravity acting on the book in order to lift it.
Thus force applied by the student on the book, F = 4.9 N
Displacement in the direction of force, s = 1.5 m
Work done, W = Fs = 4.9 `times` 1.5 = 7.35 J