Power

Definition

Power is the rate at which work is done or energy is transferred over time. It quantifies how quickly energy is utilized or converted in a system.

5 Must Know Facts For Your Next Test

1. Power is calculated using the formula $P = \frac{W}{t}$, where $P$ is power, $W$ is work, and $t$ is time.
2. The SI unit of power is the watt (W), which equals one joule per second ($1 \text{W} = 1 \text{J/s}$).
3. Power can also be expressed as $P = F \cdot v$, where $F$ is force and $v$ is velocity, when force and velocity are in the same direction.
4. In a resistive electrical circuit, power can be calculated using $P = IV$, where $I$ is current and $V$ is voltage.
5. Higher power indicates more energy transfer in a shorter amount of time.

Review Questions

• What formula would you use to calculate power if you know the work done and the time taken?
• How do you express power in terms of force and velocity?
• What are the units of measurement for power?

Related terms

Work:

Work refers to the transfer of energy that occurs when a force makes an object move; mathematically given by $W = Fd\cos(\theta)$.

Energy:

Energy is the capacity to do work or produce heat, existing in various forms such as kinetic, potential, thermal, or electrical.

Kinetic Energy:

Kinetic energy refers to the energy possessed by an object due to its motion; calculated as $KE = \frac{1}{2}mv^2$.