What happens to kinetic energy when work is done on an object?

• A. The kinetic energy decreases.
• B. The kinetic energy remains unchanged.
• C. The kinetic energy increases.
• D. The kinetic energy converts to potential energy only.

Answer: (C)

When work is done on an object, it results in a change in the object's kinetic energy. Specifically, if positive work is done, the energy transferred to the object increases its velocity, leading to an increase in kinetic energy. This relationship is described by the work-energy theorem, which states that the work done on an object is equal to the change in its kinetic energy.

For instance, if you push a stationary object, you supply energy to the object, causing it to speed up. The increase in its speed signifies an increase in kinetic energy, which is mathematically expressed as ( KE = \frac{1}{2}mv^2 ). As the object's speed (v) increases due to the work applied, the kinetic energy (KE) certainly increases as well.

In scenarios where negative work is done or energy is lost due to friction, the kinetic energy would decrease. However, the core idea here is that work, in its essence, can result in a net increase in kinetic energy depending on the context of the situation. Therefore, when work is done on an object, it typically leads to an increase in the kinetic energy of that object.