You have to do the math of each and see which one adds up to 66.5
Answer:
4 hertz
Explanation:
The defination of freqyency = the total no of cycle made by a wave in one second .
so,
cycle or vibrations=60
tame taken = 15
now,
frequency = no. of cycle / time taken
= 60/15
=4 hertz
hence, the its frequency = 4hertz
Answer:
Y = V / f where Y equals wavelength
4 Y1 = V / f1 for a closed pipe the wavelength is 1/4 the length of the pipe
2 Y2 = V / f2 for the open pipe the wavelength is 1/2 the length of the pipe
Y1 / Y2 = 2 = f2 / f1 dividing equations
f2 = 2 f1
the new fundamental frequency is 2 * 130.8 = 261.6
(The new wavelength is 1/2 the original wavelength so the frequency must double to produce the same speed.
The answer is Ultraviolet