Friday, February 16, 2007

Energy "Lost"

How many calories of energy are "lost" by a 250mL sample of water that has a temperature decrease from 52 deg. Celsius to 24 deg. Celsius?

6 comments:

Thor God of Thunder *Thomas F said...

Hi,
I believe that it lost 7000 cal. of energy. I believe that because it lost 26 degrees. Since a little cal. is how much energy it takes to raise 1 ml of water 1 degree. So I multiplied 28 by 250. That is how i got 7000 cal.

Thomas

Addie said...

Mr. Wilson, is that correct?

lauren w. said...

Didn't it lose 28 degrees not 26?

Sydney said...

I believe it lost 7000 calories of energy. The specific heat of water is 1cal/gram*degree celsius and the mass was 250 grams. The temperature difference was 28 degrees celsius. 250g x 28 degrees x 1cal/gram x degrees celsius = 7000 calories.

Vivek Biswas said...

I think that it lost 7000 calories. According to our last test, the formula for determining the energy loss is (mass)(change in temp.)(CP of Water). The mass us 250g x 28 degrees Celsius x 1 cal/(g)(degrees Celsius). The units of g and degrees Celsius cancel out so you are left with 250 x 28 x 1cal = 7000 cal.

hnori said...

Vivek basically summed it up...I agree with him, because his formula is correct and his calculations are correct.