# Homework Help: How to work out Electrical Energy

1. May 13, 2010

### LatexZone

1. The problem statement, all variables and given/known data

Can you please give me some questions and I will see if I can work out the electrical energy?

2. Relevant equations

This is what I am going to be working from (Please tell me if it's not correct):

Energy = Power x Time OR E=Pt
Power = Current x Voltage OR P=IV
Substitute
Energy = Current x Time x Voltage OR E=ITV

3. The attempt at a solution
N/A

2. May 13, 2010

### mgb_phys

Yes thats correct

ps. In electrical stuff you generally use 'Q' for energy, because E can also mean voltage or electric field in some equations

3. May 13, 2010

### LatexZone

Thanks for verifying, but can you give me any scenarios (questions) where I can use the formula to work out the answer?

4. May 13, 2010

### mgb_phys

Electric water heater?

You have 230V and 13Amps, how much energy/sec does it put into 1kg of water?
How long does it take to heat 1kg of water form 20C to 100C ?

5. May 14, 2010

### Staff: Mentor

Less than 2 minutes.