10. Give one example where work done on an object is zero.

Understanding Work Done on an Object

Introduction: In the realm of physics, the concept of work done on an object holds significant importance. Work is defined as the force applied to an object over a distance, causing it to move. However, there are instances where the work done on an object is zero. Let's explore one such example.

Example: Work Done on a Stationary Object

Scenario: Consider a book resting on a table. You exert a force by pressing down on the book with your hand, but the book doesn't move.

Explanation: In this scenario, despite applying a force to the book, there is no displacement in the direction of the force. Therefore, the work done on the book is zero.

Factors Contributing to Zero Work:

• No Displacement: The book remains stationary; hence, there is no displacement along the direction of the force.
• Perpendicular Force: If the force you apply is perpendicular to the direction of potential motion, no work is done. In this case, the force of gravity pulling the book downward is balanced by the normal force exerted by the table upward, resulting in zero net force in the direction of motion.
• Magnitude of Force: Even if you apply a significant force, if it doesn't result in any displacement in the direction of the force, the work done is zero.

Conclusion: Understanding the conditions under which work done on an object is zero is crucial in grasping the concept of work in physics. In scenarios where there is no displacement or the force is perpendicular to the direction of potential motion, the work done on the object is zero.