# How much energy does the kettle transfer?

1. Sep 15, 2004

### Christopher

I know that Tom wants us to at least have one go at answering the question ourselves but Ihave been haunted by this question for almost a week now and I don't feel ay closer to answering it.

I have been given the electron charge which is 1.6*10-19 C and I have been given the question "An electric kettle is labelled "230V, 2.3kW". It takes 2.5 minutes to boil some water.
How much energy does the kettle transfer?

How am I meant to answer this questin if I am not given some sort of other energy to compare the electric enegy to?

Chris

Last edited: Sep 15, 2004
2. Sep 15, 2004

### Christopher

ps: the italic -19 is meant to be a small -19 above to the right of the 10.

3. Sep 15, 2004

### Chi Meson

You have been given voltage and power. Power is the rate of energy transfer(P = E/t) . So "watts" = "joules"/"seconds" therefore, E = Pt "joules" = "watts" x "seconds" . You don't need the charge of the electron nor the voltage for this problem.

4. Sep 15, 2004

### Christopher

Thankyou
It never seemd to occur to me that power is the energy transfer but now it makes so much sense I feel quite stupid...lol! :rofl:

Last edited: Sep 15, 2004
5. Sep 15, 2004

### Chi Meson

That's what Physics is all about!