Question

Aman is a student of class 9. he was waiting for a bus on bus stand. he saw an old man trying to keep his box on the roof of a bus but was unable to do so. aman picked up his box and placed the box on the roof of the bus. the old man thanked aman. 1. Is the work done by gravity on the box is positive or negative? 2. what values are shown by aman?​

Answer 1

The work done is negative.

The force is negative.

which is F =m×g

in the following case g= -9.8 m/s^2

and that's why the work done will be negative.

This is because the box is being placed against gravity.