## energy equation

Tinisha 1G
Posts: 69
Joined: Fri Sep 28, 2018 12:17 am

### energy equation

How do I know when to use just the equation E=hv or when to use E=(hc)/v to find the energy of a photon?

zoepamonag4C
Posts: 30
Joined: Fri Sep 28, 2018 12:28 am

### Re: energy equation

did you mean E = hc/λ?

daniella_knight1I
Posts: 57
Joined: Fri Sep 28, 2018 12:18 am

### Re: energy equation

You will know depending on the variables given. If the variables don't quite line up with the energy equation, most likely you will have to use the other one and see if that works. Also make sure you distinguish the variable the problem is asking for.

ariana_apopei1K
Posts: 89
Joined: Fri Sep 28, 2018 12:27 am
Been upvoted: 1 time

### Re: energy equation

I think it depends on what the question already gives you data-wise. If one of the equations isn't possible to use because a specific data point isn't given, then switch to the other and see from there.

Javier_Ochoa_DIS_3J
Posts: 33
Joined: Fri Sep 28, 2018 12:23 am

### Re: energy equation

The above poster is correct.

The equation you are looking for is E = hc/λ

λ = wave length
E = energy
h = Planck constant
c = speed of light

H and C will be provided in the information sheet in the test.