What is the change in potential energy when a 12 N book is raised from a table 75 cm above the floor to a shelf 2.15 m above the floor?

An object kept at a height has a potential energy due to
the gravitational force of attraction of the Earth. This potential energy is acquired as
work has to be done to raise the object.

The gravitational
potential energy is equal to m*g*h, where m is the mass of the object, g is the
acceleration due to gravity and h is the height.

The book
weighs 12.0 N. This gives m*g = 12 N.

When the book is kept
on the table 75 cm above the floor it has a potential energy of 12*0.75 = 9
J.

On the shelf which is 2.15 m above the floor the
potential energy is 12*2.15 = 25.8.

This gives the change
in potential energy when the book is raised from the table and placed on the shelf as
25.8 - 9 = 16.8 J.