it is said that if we push a book on a table some work is done but the angle between gravity and force applied is 90degree so how does work is done or not

Question

it is said that if we push a book on a table some work is done but
the angle between gravity and force applied is 90degree so how does
work is done or not

Christelle Juliana David · Accepted Answer

When we push a book work is done because there is force(friction)
and energy applied on it
But when it is on the table the object is stationary hence there is
no work done whenever the object is 90 degree or it is stationary
work is not done