How much work does a 100-watt light bulb do when it is lit for 30 seconds?

Question

theeric · Answer

Hi!
The answer is actually pretty simple AFTER you know what power is! Power is the amount of work done per some amount of time. Any kind of work is considered. Lifting a box, or producing light.

So, we can put that in math to be
$P=\dfrac Wt$

Note that the watts are a unit of power, and, of course, seconds are time. A joule is a watt times a second, and so there you have your units.

Good luck!

theeric · Answer

In the equation,

$P$ is power
$W$ is work
$t$ is time

anonymous · Answer

@theEric 
So would that mean that if you multiply 100 by 30 you would have your answer?

theeric · Answer

Right! Because, if you do some algebra,
$P=\dfrac Wt\quad\implies\quad
W=P\ t$

That's just multiplying by $t$, actually.

anonymous · Answer

Thank you!

theeric · Answer

You're welcome! :)