Question

In which of the following situations has work been done? Select one: a. A weightlifter holds a 50kg barbell over his head for 3 minutes. b. A yoga instructor holds a handstand for 1 minute. c. A man pulls against a stationary fire truck for 5 minutes. d. A child pushes a 2kg toy 10m across the floor.

Answer 1

Work done = Force * distance --- In other words, for work to be done, a force should be applied such that there is motion.

Therefore, the only situation meeting the criteria is situation d. where a force is applied resulting to motion.