4. a tuning fork is held over a resonance tube, and resonance occurs when the surface of the water is 12 cm below the top of the tube. resonance occurs again when the water is 34 cm below the top of the tube. if the air temperature is 23 ˚c, find the frequency of the tuning fork.

As we know that speed of sounds is given as

here we know that

t = 23 degree C

now from above equation we will have

now we also know that distance between two consecutive resonance length is half of the wavelength

now we know that

so frequency will be 786 Hz

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.