# QUantum physics !

1. Sep 25, 2007

### vicks

Consider a potential energy barrier like that of Fig. 38-15 but whose height U0 is 5.4 eV and whose thickness L is 0.73 nm. What is the energy of an incident electron whose transmission coefficient is 0.0017?

I tried to solve the problem my self but could not get the right answer still having trouble with this question please let me help with this my answer is .203 but not right if some one help me out with this questino and tell me the answer would appriciate that !!! thank you very one here are the hint !

The transimission coefficient for a barrier of height U0 and width L is given by
T = e-2bL ............1
Where b = v (8p2m(U0 - E ) / h2 ) ............2
Substituting values in equation (1) we get b
Then substitute b in equation (2) we get E
Givem that U0 = 5.4 eV
m = mass of electron
L = 0.73 nm
T = 0.0017

2. Sep 25, 2007

### vicks

Quntum physics ! barrier energy !

Consider a potential energy barrier like that of Fig. 38-15 but whose height U0 is 5.4 eV and whose thickness L is 0.73 nm. What is the energy of an incident electron whose transmission coefficient is 0.0017?

I tried to solve the problem my self but could not get the right answer still having trouble with this question please let me help with this my answer is .203 but not right if some one help me out with this questino and tell me the answer would appriciate that !!! thank you very one here are the hint !

The transimission coefficient for a barrier of height U0 and width L is given by
T = e-2bL ............1
Where b = v (8p2m(U0 - E ) / h2 ) ............2
Substituting values in equation (1) we get b
Then substitute b in equation (2) we get E
Givem that U0 = 5.4 eV
m = mass of electron
L = 0.73 nm
T = 0.0017

3. Sep 25, 2007

### malawi_glenn

What is fig 38-15? =P

4. Sep 25, 2007

### vicks

don;t worry about the figure ? its in the book i cannot tell you the right here but has nothing to do with the answer .. acutally .203 i just plugin the values but i am sure i am not right so plz help me out i already set up the equation but still getingg problem to solve this problem !or to find of the energy ..

5. Sep 25, 2007

### malawi_glenn

It is straightforward, trivial. You have all values except one right?

Why dont you post your attempt to solution so that we may put you in the right direction instead?