Wattages

[physicsdude]

This is a noob question, but I'm curious about this. On many electrical products, it says that it consumes like 5 watts. Is this per hour or am I totally off base and misinterpeting it? It sounds dumb, I know, but I was just wondering how to take these things into account when computing my power bill for aqaurium usage and other thinsg for that matter. I've always assumed its done per hour, but I was curious how wrong I am!

 

[hashbaz]

physicsdude, I'm sure this will ring a bell. A watt is a continuous drain. 1 watt = 1 joule per second.

A joule is a measurement of energy. The electric company charges you based on energy: 1 kilowatt hour = 60,000 joules

5 watts * 720 hrs per month = 3.6 kilowatt hours (about $0.40) per month

 

[SparKy697]

physicsdude, I'm sure this will ring a bell. A watt is a continuous drain. 1 watt = 1 joule per second.

A joule is a measurement of energy. The electric company charges you based on energy: 1 kilowatt hour = 60,000 joules

5 watts * 720 hrs per month = 3.6 kilowatt hours (about $0.40) per month

Well done.

 

[physicsdude]

ROFL! I know! But my girlfriend thought I was wrong and it was something else! Ah well. She wont believe anything I tell her, just what other people she doesnt even know tell her. Maybe I should start a thread here asking if the sky is REALLY blue!!!!! That migh make her think twice on that one!

 

[hashbaz]

ROFL! I know! But my girlfriend thought I was wrong and it was something else! Ah well. She wont believe anything I tell her, just what other people she doesnt even know tell her. Maybe I should start a thread here asking if the sky is REALLY blue!!!!! That migh make her think twice on that one!

That makes a lot more sense! I really wondered why someone named "physicsdude" was asking a question like that.

 

[Idealconcepts]

To make things even clearer, cost will depend on how much you electric company charges per KWh. Some charge as low as 6-7 cents and as high at 12-14 cents per Kwh, this can also vary depending on the season and if you electric company has tiers.

 

[gu2high]

Is your following math has problem?

1 watt = 1 joule per second.
1 kilowatt hour = 60,000 joules

If based on 1 watt = 1 joule per second, then,
1 kilowatt hour = 1000 (joule per second) X 3600 (second) = 3,600,000 joules

Do I interpret correctly?

 

[tropicfishman]

don't ask me I'm a musician lol

 

[hashbaz]

Is your following math has problem?

1 watt = 1 joule per second.
1 kilowatt hour = 60,000 joules

If based on 1 watt = 1 joule per second, then,
1 kilowatt hour = 1000 (joule per second) X 3600 (second) = 3,600,000 joules

Do I interpret correctly?

Holy smokes! I feel stupid. You are correct. 60,000 Joules = 1 kilowatt minute not a kilowatt hour.