The popcorn-maker’s power is 250 W.

Quick Scoop

Power is the rate of energy transfer per second, given by the formula P=EtP=\frac{E}{t}P=tE​.

Here, the popcorn-maker transfers 250 J of energy every 1 second, so its power is P=250textJ1texts=250textJ/s=250textWP=\frac{250\\text{J}}{1\\text{s}}=250\\text{J/s}=250\\text{W}P=1texts250textJ​=250textJ/s=250textW.

The watt is the standard unit of power, equal to one joule per second.

So, the popcorn-maker has a power rating of 250 watts, meaning it transfers 250 joules of energy each second while it is operating.

TL;DR: Power === energy per second === 250 W.