# Electron microscope

1. Feb 21, 2006

### UrbanXrisis

electrons in an electron microscope are accelerated form rest to a momentum making their wavelength 0.06 nm.

1. what is the voltage Vo needed for this?

2. What is the final electron velocity?

For 1.

$$E=\frac{hc}{\lambda}=\frac{1240eVnm}{0.06 nm}$$
solve for E

For 2.

$$E=.5mv^2$$
Solve for v plugging in E from #1 and m=mass of electron

is this the correct thought process?

2. Feb 22, 2006

### phucnv87

I think that the correct process for classical mechanic.

3. Feb 22, 2006

### UrbanXrisis

i'm not sure I understand what you mean

4. Feb 22, 2006

### inha

This is just a guess but I think he might mean relativistic corrections. I don't think those are absolutely neccessary because the electrons energy would be roughly 20keV which is still quite a bit smaller than it's rest energy.

5. Feb 22, 2006

### UrbanXrisis

oh, you mean for part 2, i should use $$E=\sqrt{(pc)^2+(mc^2)^2}$$?