Converting (having major trouble)

[BunDa4Th]

I have a link to the image i am having trouble with it is D where i have to convert one SI unit, but really confuse how to do it.

http://img267.imageshack.us/img267/9623/webassignvy9.jpg

any help or explanation on how do the conversion would be very helpful.

 

[cepheid]

Okay, I'll get you started. From your responses to the quiz, it is clear that you realize that:

1 W = 1 J/s

Therefore, 1 J = 1 W*s

A joule of energy is the amount of energy expended after one second by something that uses one watt of power.

Therefore

1 kWh = ? W*s

well, how many watts in a kilowatt? How many seconds in an hour? It's really as simple as that!

 

[BunDa4Th]

1 kWh = (10^3 W)(3600 sec.) = 3600000 W*s

BTW, its not a quiz it's homework given to us to review for the quiz/test.

 

[cepheid]

Ok, hw. Cool...

So your answer looks right to me. In which case, if I'm reading your homework right, the cost is 7 cents per 3 600 000 joules = whatever

Let me know if that gives you the right answer!

 

[BunDa4Th]

7 cent is incorrect which i have tried earlier.

 

[cepheid]

No no no! It's 7 cents for every kWh = 3600000 J. They want to know what it is on a PER JOULE basis. Now that you have the number of joules in a kWh, you can easily calculate the unit price PER JOULE.

the cost is 7 cents per 3 600 000 joules = whatever

You were supposed to calculate the "whatever". That is your answer.