# Homework Help: Help, Physics newbie!

1. Mar 13, 2005

### chibi_lenne

I know this is probably really really REALLY basic physics, but I'm not too good with it. (still doesn't understand why a massage therapist needs physics, but whatever). Unfortunately being a Sunday, and me taking this class through correspondence...my tutor isn't available. And I feel REALLY stupid about this. anywho...here's my problem.

Two Vibrating sources emit waves in the same elastic medium. The first source has a frequency of 25Hz, while the frequency of the second source is 75Hz. Waves from the first source have a wavelength of 6.0m. They reflect from a barrier back into the original medium, with an angle of reflection of 25degrees. Waves from the second source refract into a different medium with an angle of incidence of 35degrees. The speed of the refracted waves is observed to be 95m/s.

What is the speed of the waves from the second source in the original medium? Explain your answer.

Okay, so here's what the problem for me is....The first part of the question (not posted here) was to find the speed of the waves of the first source, no problem there. The thing is, to find the speed of the waves from the second source, they didn't give a wave length. Can someone help me make sense of all this mush? I've been working on it most of the afternoon and my brain's at about melt down point
.

2. Mar 13, 2005

### chibi_lenne

please someone throw me a bone...this problem is really bugging me and grating on my nerves.

3. Mar 14, 2005

### chibi_lenne

WELL this is just a LITTLE discouraging, no help from a help board. Cand someone PLEASE try and help me out a little bit here?

4. Mar 14, 2005

### HallsofIvy

Are you aware that the wave speed in a given medium depends ONLY on the medium?
That is the wave speed of waves from the second source is the same as the wave speed of the waves from the first source.