Question

The potential energy of a system increases if work is done

• A. upon the system by a nonconservative force
• B. by the system against a conservative force
• C. by the system against a non conservative force
• D. upon the system by a conservative force

Hint:

Potential energy refers to the energy possessed by an object due to its position

Answer 1

The Correct Option is B

The question asks about the conditions under which the potential energy of a system increases. Let's break down the options one by one to understand which scenario leads to an increase in the potential energy.

1. Upon the system by a nonconservative force: Nonconservative forces, such as friction or air resistance, generally do not store energy in the form of potential energy. Instead, they convert mechanical energy into other forms, such as thermal energy. Therefore, work done by nonconservative forces does not increase potential energy.
2. By the system against a conservative force: A conservative force, like gravity or an elastic spring force, has an associated potential energy. When work is done by the system against a conservative force (for example, lifting an object against gravity), potential energy increases. This is because work done against such forces is stored as potential energy, making this the correct option.
3. By the system against a nonconservative force: Similar to the first option, when the system does work against a nonconservative force, energy is generally lost to other forms and does not contribute to an increase in potential energy. This scenario usually leads to a loss of mechanical energy.
4. Upon the system by a conservative force: When work is done upon the system by a conservative force, energy is transferred to kinetic energy or is converted into potential energy, but since the work is done upon the system, potential energy does not necessarily increase. It may simply convert mechanical energy without a net gain in potential energy.

Therefore, the correct answer is: by the system against a conservative force. This scenario clearly describes the increase in potential energy as work is effectively stored in the form of potential energy.