If power costs, 8.0 cents/MJ, the cost(to the nearest dollar) to operate a 1500 W heater for 20 minutes a day for 300 days would be what amount of money?
2006-11-04 10:54:09 · 4 answers · asked by Kameliya 2 in Science & Mathematics ➔ Physics
Ok, here's what you have
Power cost = 8 cents/MJ
Power of the heater = 1500 W
time = 20 minutes/day * 300 days = 6000 minutes*60s/min = 360000 secs
cost = ?
OK, first of all you have to understand what a watt is (W), this is a watt
1 Watt = 1J/s
where J is Joule and s is second, soooo
(8 cents/1000000J)*(1J/(1W*s))*(1500W)*(360000s) = 4320 cents
4320 cents * 1dollar/100cents = 43.2 dollars
The nearest dollar = 43 dollars
Hope this helps
2006-11-04 11:11:24 · answer #1 · answered by mensajeroscuro 4 · 0⤊ 0⤋
First, determine the number of J used. 20 min is 1200 s. A W is a J/s, so the daily energy use is 1500*1200 = 1.8e6 J. 1.8e6*300 = 540e6 J, or 540 MJ, per year. 540*0.08 = $43.20
2006-11-04 21:24:55 · answer #2 · answered by pack_rat2 3 · 0⤊ 0⤋
A MJ = MW*sec
2006-11-04 19:07:24 · answer #3 · answered by arbiter007 6 · 0⤊ 0⤋
$480.00? with the added chance of you freezing your tail off
2006-11-04 19:01:32 · answer #4 · answered by krusty_blue_spaz 5 · 0⤊ 1⤋