Recent content by maxelcat

I understand that if the sun where to 'disappear' then it would take several minutes for the us on the earth to notice as the light takes time to travel. Does this mean that it would also take the same time for us to notice that the gravitational (or electromagnetic) force would disappear too...

I believe that when a photon is refracted it slows. Why is it that the wavelength decreases but that its frequency stays constant? Does this imply that the photon has not lost any energy in the process of slowing down given that E=hf? Thanks

thanks Dale. I figured this wouldn't be an easy answer

I believe that when a photon is refracted it slows. Why is it that the wavelength decreases but that its frequency stays constant? Does this imply that the photon has not lost any energy in the process of slowing down given that E=hf? Thanks

thanks for your reply. Having now looked at the examiners report, and bearing in mind this was 2021 when things seemed to be up in the air exam wise, I think they wanted you to justify - so if you said something along the lines of 'looking at the plan view into the page' or 'assuming the pointer...

I use FLHR and the plan diagram. This suggests that the left hand side of the coil is going down. I have added annotations to this, which agree with the mark scheme which then goes onto suggest that the coil turns clockwise. To me though this would make it go anti clockwise. So... what am I...

no I think P and Q are in phase (both reaching their max at the same time - thanks for the explanation - very helpful

actually it is there because the question is to identify which is antiphase

I think I understand that points P and R are pi radians out of phase - reaching their max/min at the same time. But are P and Q in anti phase? What is antiphase exactly - is it when they are 180deg out of phase - or is it when they are anything other than totally in phase? I seem to find...

and yes, it is not an escape velocity question. D'oh - I see that now. Thanks

yes - found that.

This is a multiple choice question. I assumed that this is an escape velocity question. I have been going round and round... Here's what I have done:

Yes - I can see that. I misunderstood what it meant about 'lightly'. Thanks all. (BTW this is an AS level q so it shouldn't be hard!)

so that would mean there is only going to wave - the shorter one

that is how i read it. so string vibrates in two sections one of lenth 2L/3 and one L/3