Amount of watts needed to heat water

[wakejosh]

I have a problem where I have a cup of water and I have to find out how much power I need to generate to heat it by a certian amount. I can't seem to find the equation I need in my book, can someone help me out? thanks.

 

[berkeman]

The definition of a calorie should get you going:

http://en.wikipedia.org/wiki/Calorie

 

[wakejosh]

ok., now I am just trying to figure out how many watts = a calorie. is it 0.239 calories = 1 watt?

 

[berkeman]

Keep in mind that a calorie is a unit of energy, and a watt is a unit of power. Do you know how to convert from power to energy? (hint -- keep track of your units so you don't mix seconds and hours, etc.)

 

[wakejosh]

i don't know, how do i convert watts to calories?

 

[berkeman]

i don't know, how do i convert watts to calories?

It says how right at the top of the wikipedia page that I posted a link to. Use the small calorie (gram) definition.