Recent content by astrorob

Hi Lothar, You first need to calculate the force exerted due to friction, the equation for this can be found here: http://en.wikipedia.org/wiki/Friction Have you been supplied with a distance that the crate is pushed?

What do you mean "a green cloth"? You mean when illuminated with white light the cloth appears green?

Hi m.l. In regards to a), I think you're probably correct. It seems reasonable that the larger the object, the more intense the reflected sound wave. In regards to b), I think you're also correct. If the insect is moving away, the echo returned by the object would have a lower pitch due...

Hi again electricblue, You're going to have to show some attempt before we can help you. Hint: Use N2L and also work out the maximum frictional force before slipping.

Careful here. They correspond to points of maximum amplitude but in regards to their physical positions, they must be differentiated (i.e. by the use of maxima/minima).

Yes it is. Note the 2 on the RHS corresponding to 2 consecutive peaks/troughs of maxima OR minima.

Hi ZaZu, I'm not 100% of what you're asking so if I'm telling you something you already know - forgive me. I presume the experiment involves counting how many maxima OR minima of a standing wave propagating between two fixed points, the distance between which you know already. In this...

Hi electricblue, To make you understand this concept, consider a block placed on an angled slope. The block can either; 1. Slide (the frictional force exerted on the slope by the contact surface of the object < the force component due to gravity acting on the block parallel to the...

I have to ask, what are you trying to do? "uhmm, say I have half of a parabolic curve, how do I turn it into a straight line?" That doesn't really make sense.. Are you trying to find the gradient of the curve at a point?

Firstly, be careful of the equation you use. The equation you state is for charge - but you're interested in current. In this case you're safe since the equations are exactly similar, but you might faulter in the future if you're not careful.. It may be useful to rearrange the equation before...

Remember, as mgb_phys stated, Rayleigh's Criterion expresses the angular distance in radians. If you're still getting the incorrect answer I suggest you explicitly post how you're calculating the distance.

If you don't know what angle its entering the medium relative to the normal then how are you supposed to know if it will internally reflect? It could either exit the medium on the second face or bounce around inside for a while... As a best guess, and this seems so entirely unphysical that it...

I don't understand how you're expected to solve that without the incident angle and also the angle at which the glass is sloped on the left hand side.

Are we told the angle at which the light is incident on the glass? Is it incident normally (at 90 degrees)?

Hi oro, Apologies but I don't quite understand what you're question is. If you wanted to solve the Rankine-Hugoniot condition for energy flow for something other than a monatomic gas, what's the problem with just plugging in a different value of \gamma into equation 3 in your list?