Answer:
Force on the object is 20 N
Explanation:
As we know that work done to raise the book from initial position to final position is known as potential energy stored in it
So here we know that
[tex]U = F.s[/tex]
here we know that
U = 30 J
s = displacement = 1.5 m
so we have
[tex]30 = F(1.5)[/tex]
[tex]F = 20 N[/tex]