# Homework Help: Energy from a 60-watt bulb

1. Dec 21, 2005

### AngelShare

I'm not sure I'm doing this correctly...

If all of the energy from a 60-watt bulb was put into 1 gram of water at room temperature for 2 seconds, how much would the temperature of the water increase?

I tried it using the example but I wanted to check my answer first.

60 * 2 = 120
120 / 4.1868

29 degrees Celsius?

2. Dec 21, 2005

### Unco

That's correct; nice work.

Don't be afraid to show the formulae you use, though.

3. Dec 21, 2005

### AngelShare

Ah, that's good.

Actually, I don't know the formula. I was using the example on this site http://ippex.pppl.gov/interactive/energy/calorie.html" [Broken].

Last edited by a moderator: May 2, 2017
4. Dec 21, 2005

### Unco

$$P = \frac{\Delta E}{\Delta t} \Rightarrow \Delta E = P \Delta t$$

$$\Delta E = mc \Delta T$$

They're a little useless if you've never covered the concept, though, I suppose.

Last edited: Dec 21, 2005