Physics - Power
Energy
What is power?
Power is the rate at which work is done.
What is the symbol formula for power?
\[P = \frac{W}{t}\]
If velocity is the rate of change of displacement, work done is?
The rate of change of energy.
What is the unit of power?
\[\text{watt}, W\]
What is the equation for power in terms of velocity?
\[P = Fv\]
How is efficiency calculated?
\[\frac{\text{useful output energy}}{\text{total input energy}} \times 100%\]
2021-02-03
If
\[P = \frac{W}{t}\]
and
\[W = VQ\]
How could you write the formula for $P$?
\[P = \frac{VQ}{t}\]
\[P = \frac{VQ}{t}\]
How could you rewrite this?
\[P = IV\]
What is electrical power?
The rate of energy transfer per component.
What are the units for power?
\[W, \text{watts}\]
If
\[V = IR\]
and
\[P = IV\]
How could you rewrite the power equation?
\[P = I^2R\]
If
\[I = \frac{V}{R}\]
How could you rewrite the power equation?
\[P = \frac{V^2}{R}\]
Given a power, $P$, how can you calculate the work done $W$ over a given time $t$?
\[W = Pt\]