Recent content by nina

This is NOT my homework, I am not being marked on it... but it is a matter of balance. Please someone answer, I'm in desperate need!

Homework Statement The frame must support a weight of 10kg, approximately 0.5m above the floor. The weight is suspended from the top of a vertical elipse shape, of which 1 side is missing. The bottom of the half elipse rests on a base. It looks like a slightly straighter "C" with the weight...

Thanks, but it's not homework! I'm trying to work it out for myself for another project, needed to check the answer before I went forward with the work! That IS the original question, shows why I shoudnt be a teacher!

I'm stuck on some basic physics... I'm using the formula E=mc (delta T/delta t) where E is energy, m is mass, c is specific heat, T is temperature and t is time, to calculate the energy used in heating a volume of air to a certain temperature. Assuming that pressure is of that at sea...

Thank you! Now I feel a bit stupid, I knew Q=mc^T from my Physics a couple of years ago, but didnt even see it in this one:rolleyes: Thanks again for pointing it out.

I'm stuck on a formula I'm using to design a solar water heater at uni (and no, I'm not a physics student, otherwise I'd probably be kicking myself its such a stupid question) and I understand the theory behind it, I just can't work out what the Qs stands for. ^T=Qs / mC where ^T= change...

actually, it makes sense now. thank you so much. i may just get a good grade in my exam now... :smile:

Thanks! I will look at that more closely. thanks for the link too.:smile:

Yes, I can calculate the wavelength from L. But why is there no second harmonic in a closed pipe?

Just that the 1st overtone has a frequency of 3 times the fundamental frequency, therefore the second harmonic is missing. Is that all I need to know? It doesn't seem much of an explanation to give in an exam. Thanks for your help...

Why can't closed pipes produce even numbered harmonics? I have been given an explanation, but it isn't very detailed. I'm doing A2 (or just A level) physics, so an explanation suitable for this level would be greatly appreciated! Thanks.