- #1

madeinmgs

- 2

- 0

1.) Two motorists are traveling at 90.0 km/h in the same direction on a freeway, and each is equipped with a horn, that has frequency of 350 Hz.

(a) If the from motorist sounds her horn, what frequency does the near motorist hear?

(b) If the rear motorist sounds his horn, what frequency does the front motorist hear?

**I understand that to find frequency, you take the speed of sound, depending on whether they are in front or behind each other, subtract it from the velocity of the object, and then multiply it by the frequency of the object making the sound. f' = (v - vo) / (v - vs) * fo**

But the problem doesn't tell me that one is in front of the other, do I assume they are driving side by side, and if so, does the velocity subtract or add?

But the problem doesn't tell me that one is in front of the other, do I assume they are driving side by side, and if so, does the velocity subtract or add?

A 65.0 cm guitar string has a mass of 2.60 g and is plucked so as to produce its fundamental frequency. The sound wave emitted has a wavelength of the 1.17 m. What is the tension in the string?

**This problem doesn't deal with harmonics ie.(open pipe, or closed pipe) I'm really stumped on this one. I can see trying to tackle this problem from a v = sqrt(F / u ) point. Which I think turns into a T(tension) = uV^2 But any push in the right direction would be helpful.**