3. Meera had some guests visiting on Sunday afternoon. While serving them tea from the fingers and she teels intense pain. Her mother asks her to keep her fingers under
running tap water. After some time the pain subsides,
Answer the following questions based on the above information
a) What could be the possible reason for the intense pain felt by Meera?
b) Why does her mother ask her to keep fingers under tap water?

"Work done by a constant force on an object is the product of the force and the distance moved by the object in the direction of the force" -textbook

There is work done ONLY if the direction of the force and the direction the item is moving are the same. In figure A, the direction of the force (the lifting) is upwards (defying gravity), and the book is moving upwards, so work is done. In figure B, the force is still moving upwards (the person is carrying the books) but the book is moving to the right, so there is NO work done.