Question

which of the following are formulas for power? choose all that apply.
$p = iv$
$p = \frac{\delta e}{\delta t}$
$p = \frac{f}{a}$
$p = i^{2}r$
$p = mv$
$p = dgh$
$pv = nrt$

Explanation:

• \(P = IV\): In electrical circuits, power (\(P\)) is the product of current (\(I\)) and voltage (\(V\)).
• \(P=\frac{\Delta E}{\Delta t}\): Power is defined as the rate of change of energy (\(\Delta E\)) with respect to time (\(\Delta t\)).
• \(P = I^{2}R\): Using Ohm's law (\(V = IR\)) and substituting into \(P = IV\), we get \(P=I\times(IR)=I^{2}R\) (where \(R\) is resistance).
• \(P=\frac{F}{A}\): This is the formula for pressure (\(P\)), not power. Pressure is force (\(F\)) per unit area (\(A\)).
• \(p = mv\): This is the formula for momentum (\(p\)), where \(m\) is mass and \(v\) is velocity.
• \(P = Dgh\): This is related to pressure in a fluid (where \(D\) is density, \(g\) is acceleration due to gravity, \(h\) is height).
• \(PV=nRT\): This is the ideal - gas law (where \(P\) is pressure, \(V\) is volume, \(n\) is the number of moles, \(R\) is the gas constant, \(T\) is temperature).

Answer:

\(P = IV\), \(P=\frac{\Delta E}{\Delta t}\), \(P = I^{2}R\)