Question

1. Tie a string to an empty box, as shown in the picture.
2. Pull the box through a distance of 10 metres along a straight line.
3. Now fill the same box with 20 books.
4. Pull the box again through a distance of 10 metres in a straight line. What was your experience this time?
5. Now pull this loaded box through a straight distance of 20 metres.
6. When did you feel that more work was done?

Answer 1

• When the box is filled with 20 books, it becomes heavier and more force is required to pull it through 10 metres. Therefore, pulling the loaded box is more difficult than pulling the empty box.
• The maximum work is done when the loaded box is pulled through 20 metres, because both the force applied and the distance through which the box is moved are greater.