Question

show how the alternative definition of power p=fv can be derived by substituting the definitions of work and speed into the standard definition of power p=w/delta t

Answer 1

https://quizlet.com/189119475/physics-power-flash-cards/

Answer 2

https://quizlet.com/183926903/work-and-energy-practice-flash-cards/

Answer 3

By definition of work:

\(\delta W = \mathbf F \cdot \delta \mathbf r \)

And so instantaneous Power at time \(t\) is:

\(P = \lim\limits_{\delta t \to 0} \dfrac{\delta W}{\delta t} = \lim\limits_{\delta t \to 0} \dfrac{\mathbf F \cdot \delta \mathbf r}{\delta t} \)

\( = \mathbf F \cdot \lim\limits_{\delta t \to 0} \dfrac{ \delta \mathbf r}{\delta t} \)

\( = \mathbf F \cdot \mathbf v \)