# Homework Help: Help with light, wavelength, and photons

1. Oct 21, 2005

### jewilki1

I need help with parts of this question.
6. The red light emitted from a Helium-Neon LASER has an energy of 3.15 x 10^-19 J.
a. At what speed do "red photons travel? I need help with this one.

B. calculate the wavelength of these photons.
I got 6.31424 x 10^-7m. Is this correct.

c. comment on the speeds of the photons from the LASER versus the X-ray photons. I need help with this one.

I am trying to study for a quiz and really need help.

Thanks.

2. Oct 22, 2005

### Ouabache

If you show us what you have tried so far (work) and where you are getting stuck, we can point you in a successful direction.

3. Oct 22, 2005

### jewilki1

I don't know how to do a and c, but I got the answer to b. IS b correct?
and can you help with a and c. Thanks

4. Oct 23, 2005

### Gokul43201

Staff Emeritus
We can't tell you if (b) is correct, unless you show how you got that number.

As for (a) and (c), you have to show some effort. What are your thoughts ?