Help me with a Quantum physics question

[globalcitizen]

Ok guys I need the answer by an hour. I will outline the question and I have tried working it out but I ant get the answer.

Nuclei have energy levels just as atoms do. An excited nucleus can make a transition to a lower energy level by emitting a gamma-ray photon. The lifetime of a typical nuclear excited state is about 1 ps. What is the uncertainty in the energy of the gamma-rays emitted by a typical nuclear excited state?

Ok I used the Energy-Time Uncertainty Principle:

delta(E) * delta(t) >= 1/2 h

Now there are 3 possible answers:

1) 1e-4 eV
2)3e-4 eV
3)7e-4 eV

I got 1/2h as 2.068 e-15 eV.s since h= 4.136e-15 eV.s, and I divide that by 10^-12 seconds but I get none of the answers.

Help I'm totally on this one.

 

[leftyman]

yes do your homework in off topic

 

[Kenny1234]

the equation is hbar over 2 not h/2

 

[globalcitizen]

Originally posted by: Kenny1234
the equation is hbar over 2 not h/2

Damn thanks a lot. That solved the problem. Guess I need to use my glasses next time I look at the Heisenburg equation.

 

[Fenixgoon]

what's hbar = to? i'm not in quantum physics, but still interested in this (future materials engineer here )

 

[Fritzo]

I'd give you the answer, but due to the uncertainty principle you would not be able to look at it and write it at the same time. Sorry.