# Homework Help: Passing by

1. Jun 12, 2006

### Endarmacional

I want to find out how many paricles on random move passing through a little hole ?
There is no condition or force acting on eachof them. Thanks guys

2. Jun 12, 2006

### NEWO

$$E=h\nu$$

which is the energy for one photon, then can you see what the energy of many photons is??

$$E=nh\nu$$

where n is the number of photons, hence rearrage to get n,

i presume the photons get diffracted as they go through the hole in which case

$$E=\frac{nhc}{\lambda}$$

where lambda is
$$\lambda=2d\sin\theta$$

because you haven't given information on what you are given ie what values you have, I will also give you this for a particle,

$$E=\frac{n\hbar^{2}k^{2}}{2m}$$

where

$$k=\frac{2\pi}{\lambda}$$

and as before $$\lambda=2d\sin\theta$$

also when asking questions, it is best to put more into them, your own workings and understanding and also a bit more in about the question, it is not easy to understand what you are asking with only 2 lines of writing

best wishes

Newo

Last edited: Jun 12, 2006