A person holds a bundle of hay over his head for 30 minutes and gets tired. Has he done some work or not ? Justify your answer.

A person holds a bundle of hay over zero his head of 30 minutes and get tired. Has he done some work or not ? Justify your answer.

Why does a person standing for a long time get tired when he does not appear to be doing any work ?

What is the amount of work done by a boy when (i) he holds a bundle of books of mass 2 kg for 5 minute? (ii) be lifts up the same bundle of books through 1 metre to keep it on his study table?

What is the work done by the force of gravity on a satellite moving round the earth? Justify your answer.

What is the work done by the force of gravity on a satellite moving round the earth ? Justify your answer.

What is the work done by the force of gravity on a satellite moving round the earth? Justify your answer.