MediumPhysicsHigh School (11–12)Waves & Sound › Wave MotionWaves & Sound › Superposition and Standing WavesNumerical
A musician sounds a 320 Hz fork with a sitar string and hears 5 beats each second.
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A musician sounds a fork with a sitar string and hears beats each second.
- What two frequencies could the string have?
- She tightens the string a little, and the beats slow to each second. What was the string's frequency?
Need a reminder? The key ideaShow
: the medium sets the speed, the source sets the frequency. On a string, . Two waves in step: a path difference of whole wavelengths is loud, of odd half wavelengths is quiet. Beats: each second.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. (a) or .
Step 2. (b) Tightening raises the pitch. From it would move away from , and the beats would speed up. From it moves closer, and the beats slow down, as she heard.
Answer: . She should keep tightening until the beats stop.
Discussion (0)
Log in to join the discussion.
Loading…