Give two examples of situations in which you might think you’re doing work but in which, in the technical sense, you do no work.
To explain: Two real life situations in which a person might think that he is doing work but in the technical sense, he does not.
Answer to Problem 1FTD
Walking a mile in a horizontal road, carrying a heavy wooden block over the head and pushing a strong wall, for an hour are the examples of real life situations in which a person might think that he is doing work but in the technical sense, he does not.
Explanation of Solution
Technically, the work is defined as the product of force acting on a body and the displacement of the body in the direction of applied force.
When a person is walking a mile carrying a heavy wooden block over his head, he is constantly applying a force to keep the block on the head. This force is applied vertically upward against the force of gravity and it keeps the block stable over his head. Since he is walking in a horizontal road, the there is no displacement for the block in the direction of applied force. Hence, even though he feels that he is doing work due to the energy expenditure in his body, in the technical sense, the work done is zero.
Pushing a strong wall for an hour, only results the expenditure of energy from his body, but does not make any displacement of the wall in the applied direction of force. Hence this situation also might make the person think that he have done work, but technically no work has been done in that process.
Conclusion:
Therefore, walking a mile in a horizontal road, carrying a heavy wooden block over the head and pushing a strong wall, for an hour are the examples of real life situations in which a person might think that he is doing work but in the technical sense, he does not.
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