Energy needed to keep a 75w bulb burning for 1 hour = 270kj Calculate energy neede to keep it burning for 3 hours?
In J and kcal?
I got the J: It is 270kj x 1000/1 x 3/1 = 810000=8.1 x 10^5J
But How Do I get the kcal?
1 cal = 4.184 J
1000 cal = 1 kcal.posted by DrBob222