Force applied on the book (F) = 5 N,
Displacement made by the book due to force (d) = 20 cm = 0.2 m,
Work done to displace the book (W) =?
We have, work done (W) = Force (F) × displacement (d)
= F × d
= 5 × 0.2
= 1 joule
∴ The work done to displace the book is 1 joule.