Recent content by Brammo

Ok so If I plot ε(k) against k for the nearly free electron model there will be an energy gap. Bragg refelction leads to these energy gaps and standing waves. So does Bragg reflection not ocurr in the free electron model? What materials have the property of the free electron model and what...

Brilliant thank you.

Which is more likely to cause a serious burn, 100^{o}C of water or an equal mass of 100^{o}C of steam. I was thinking that because the steam has a lower heat capacity it would do less lamage as it has a lesser ability to transfer heat. Or has it got nothing to do with heat capacity? I am a...

Homework Statement Estimate how many photons of visible light (500 nm) are emitted by a 100 W Bulb. The answer on the sheet says approximately 10^{20} photons/second However when I work it out I get a slightly different answer. Homework Equations I used that 1J=1W/s or E=P/t Also Energy...

Ok well these are practice questions written by a physics professor. The answer he has written at the bottom of the questions is approximately 10^20 photons/second. I just wanted to know where i had gone wrong if I had. The question is as above and its not something you need to pick apart I was...

(1) yes, sorry. (2) I assume it means 100w of light energy. But what would the answer be if it was electrical?

Estimate how many photons of visible light (500 nm) are emitted by a 100 W Bulb. I get 2.5\times10^{20} Photons/Second Am I correct? Thank you. EDIT: Added units.