# isaac physics question

hey could anyone help me with this question?

The total annual UK electricity production (2014) is 335TWh for a population of approximately 65million people. In the example question, we showed that when 1.0kg of hydrogen (1H) fuses to make 1.0kg of helium (4He) 650TJ of energy is released. Using this, how much hydrogen, in kg, would need to fuse into Helium to meet your individual electricity needs for one year (assuming that your electricity usage is typical of a resident in the UK)?
Have you worked out how many Joules there are in a TWh?
Original post by Joinedup
Have you worked out how many Joules there are in a TWh?
3.6*10^15 joules right?
Original post by ferdi295
3.6*10^15 joules right?
Ok so how many joules per person per year

And then how many kg of Hydrogen must be fused to produce that amount of Energy.

Unless you're given some information about the efficiency of energy conversion to electricity you'll have to assume 100% I guess.
Has anyone got the answer correct? Tried today and keep getting it wrong, would appreciate the help!
Original post by alaana
Has anyone got the answer correct? Tried today and keep getting it wrong, would appreciate the help!

It is good to show your working and also put a link to the question, so that we can check.
Original post by Eimmanuel
It is good to show your working and also put a link to the question, so that we can check.

this is the link to the original question

https://isaacphysics.org/questions/bb_energy_q3?board=ef9cb92c-9eaf-4536-8613-5314db2e8b94&stage=a_level

(it's question F)
Original post by alaana
Has anyone got the answer correct? Tried today and keep getting it wrong, would appreciate the help!

The hints should give you enough help to get the correct answer. Next, be careful about the number of significant figures.