Question

If work done on a body is positive, then what will be the sign of kinetic energy?

• A. Increase
• B. Decrease
• C. Zero
• D. Either increase or decrease

Answer 1

The Correct Option is A

If the work done by a force on a body is positive, then its kinetic energy increases. The work-energy theorem states that the work done on an object is equal to the change in its kinetic energy. When the work done is positive, it means that the force applied to the object is in the same direction as its motion, and thus the force is doing work on the object to increase its kinetic energy.
Mathematically, the work-energy theorem can be expressed as:
Work = Change in Kinetic Energy
If the work done (W) is positive, then the change in kinetic energy (ΔKE) is also positive. This indicates that the object's kinetic energy has increased, which means it has gained speed or motion as a result of the force applied to it.
It's important to note that the work done on a body is the net work, which takes into account all the forces acting on the object. If there are multiple forces acting on the body, the net work done by all the forces will determine the change in its kinetic energy.