Sita sits motionless on a bench holding a heavy school bag on her lap while waiting for her bus.…
Sita sits motionless on a bench holding a heavy school bag on her lap while waiting for her bus. Scientifically, how much work is done on the bag while sitting?
A large amount of work because the bag is heavy
Zero work because there is no displacement of the bag
Negative work because gravity pulls it downward
Work depends on how long she sits on the bench
Solution
For scientific work to be done, a force must cause displacement of the object. Since the bag does not move, the displacement is zero and no work is done.