Power is defined as which of the following?

The definition of power is fundamentally tied to the concept of work done over a period of time. Power quantifies how quickly work is performed or how fast energy is transferred or converted. When we say power is equal to work done divided by time, we are expressing the rate at which energy is used or produced. This relationship is foundational in engineering and physics, particularly in scenarios involving machines, engines, and various types of energy systems.

In contrast, the other options pertain to different physical concepts:

• The expression for force multiplied by distance relates to work, not power. Work is calculated as the force applied over a distance.

• Mass multiplied by height is a calculation linked to gravitational potential energy, which measures the energy stored due to an object's position in a gravitational field.

• Dividing energy by mass yields a quantity that does not directly represent power; instead, it has implications in contexts like specific energy, which is the energy per unit mass (often used in thermodynamics and engineering).

Thus, defining power as work done divided by time accurately captures its meaning as the rate of energy transfer or conversion, making it the correct answer.