Question

An eraser is tied to a string; a person holds the string and applies a tension force as the eraser is moved in a circle at constant speed. This is an example of work being done.

Option 1: True
Option 2: False

Answer 1

No work is done when an eraser is moved in a circle at constant speed, despite tension in the string, because the displacement is perpendicular to the direction of the force.

Step-by-step explanation:

When an eraser is tied to a string and moved in a circle at constant speed, this is an example where no work is being done. The Work-Energy Theorem states that work is only done when a force causes a displacement in the direction of the force. In the circular motion scenario, even though there is tension in the string, the force provided is centripetal, meaning it acts perpendicular to the direction of the eraser's velocity at all points in the path. Since the displacement is always perpendicular to the tension force, no work is done. Therefore, the statement that work is being done on the eraser in this case would be false.