So if its open at one end and closed at the other fundamental frequency occurs at 0.25 the wavelength? And if its closed/open at both ends its at half the wavelength?
Around 70/100 for an A, low 60s for a B, around 55 for a C
Cheers, think I need 130 UMS for an A (unless my retake improves my unit 1 score). And about 100 UMS for a B which is probably more likely unless we get a nice paper.
Cheers, think I need 130 UMS for an A (unless my retake improves my unit 1 score). And about 100 UMS for a B which is probably more likely unless we get a nice paper.
Good luck! I think I need around 105 UMS for an A if my G491 went as well as I think it did. Just hope they don't ask us any tricky questions on the pre-release as I haven't done much work on that
Is this anyone's last exam? Mine is. I'm so unmotivated for this. Argh
Precisely what I thought last summer (well actually I got heatstroke just before). This is my third time resitting it as I need the grades for uni.. Don't do it to yourself!
could someone pleaseee explain the photoelectric effect? Thanks so much
Basically UV light was shone onto a metal plate and if the electrons on the surface absorbed enough energy, they could escape from the surface. There were 3 observations that suggested electrons act as particles: 1) There was a minimum frequency (called threshold frequency) that the electrons needed to absorb before they could escape 2) Increasing the frequency increased the kinetic energy of the electrons 3) Increasing the intensity increased the no of electrons that were emitted
could someone pleaseee explain the photoelectric effect? Thanks so much
It's what introduced the theory that light can't only be described as a wave.
* Threshold frequency: minimun energy photoelectrons must have to be emitted off. * Max. kinectic energy increases with increasing frequency. * No. of photoelectrons emitted per second is proportional to the intensity of the radiation.
If light was only a wave, the max. kinetic energy should increase with intensity of the wave. But it depends on frequency which mucked up wave theory.
There are some questions on the previous pages of the thread practice on them, they often turn around uncertainty and stuff you have done during your coursework