performing work is changing, it makes sense to talk about the instantaneous power, defined as

$P=\underset{t0}{lim}\frac{W}{t}$

The SI unit of power is the watt $($W$).$ One watt is defined as the power created when one joule of work is done each second. In equation form, one writes

$1W=1\frac{J}{s}$

A commonly used unit of work is the kilowatt$-$hour $($kWh$).$ One kilowatt$-$hour is the amount of work done in one hour when the power is one kilowatt. In equation form, this is

$1kWh=1kW*1$ hour

$={10}^{3}W*3\mathrm{.}6{10}^{3}s=3\mathrm{.}6MJ$

In this problem, you will answer several questions that will help familiarize you with power and enable you to derive a formula relating power, force, and velocity.