00:01
So if i'm looking to see how much energy is used by 250 million clocks in a year, what i want to do is first know how much energy each of those clocks used.
00:15
So let's say each clock uses 2 .5.
00:27
So i'm going to start this problem by breaking it down into a smaller problem where i find it for one clock, and then multiply it by the 250 million clocks to find the total answer.
00:39
So first of all, i want to convert watts to joules per hour.
00:44
I have 1 watt is equal to 3 ,600 per hour.
00:55
And so that means that i have 2 .5 of these.
01:01
So for 1 o 'clock, 2 .5 times 3 ,600 joules per hour is going to give me 9 ,000 joules per hour.
01:19
So now i need to figure out how many hours are in a year so i can convert this hours here into one year, because that's the amount of time i'm looking at.
01:30
So i have 24 hours per day and 360 days per year.
01:46
And what that gives me, days cancel out here, and i have 8 ,760 hours in one year.
02:01
All right.
02:03
So now i can figure out how much energy is used by one clock...