Average power

Definition

Average power is the rate at which work is done or energy is transferred over a period of time. It is mathematically defined as the total work done divided by the time interval during which the work was done.

5 Must Know Facts For Your Next Test

1. Average power is calculated using the formula $P_{avg} = \frac{W}{\Delta t}$, where $W$ is work and $\Delta t$ is the time interval.
2. The SI unit of average power is the watt (W), equivalent to one joule per second ($1\, W = 1\, J/s$).
3. Average power can also be expressed in terms of force and velocity: $P_{avg} = F \cdot v$, where $F$ is force and $v$ is velocity.
4. In oscillatory systems, average power can be related to amplitude and angular frequency.
5. Understanding average power helps in analyzing energy consumption in mechanical systems, electrical circuits, and real-world applications like engines and machinery.

Review Questions

• How do you calculate average power if you know the total work done and the time interval?
• What are the units of average power?
• Explain how average power can be expressed in terms of force and velocity.

Related terms

Work: Work refers to the process of energy transfer when a force acts upon an object causing displacement. Mathematically, it’s calculated as $W = F \cdot d \cdot \cos(\theta)$.

Kinetic Energy: Kinetic energy is the energy possessed by an object due to its motion. It’s given by $KE = \frac{1}{2}mv^2$, where $m$ is mass and $v$ is velocity.

Instantaneous Power: Instantaneous power is the rate at which work is done or energy transferred at a particular moment in time. It’s calculated as $P(t) = \frac{dW}{dt}$.