Physics
In a shopping mall, while standing on an escalator you move from level 1 to 30 metre high level 4. What is the work done by you?
Answer
When I stand still on the escalator, I’m not applying an upward force through the 30 m height, so the work done by me is 0 J (approximately zero). The escalator’s motor provides the upward force and does the work equal to mgh to lift me to level 4. (If I had climbed myself, then I would have done mgh work.)
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