Question 488: Waves

Question

A string is stretched between fixed  points separated by 75.0 cm. It is observed to have resonant frequencies of 420 Hz and 315 Hz.  There are no other resonant frequencies between these two. The lowest resonant frequency for this  string is

Accepted Answer

In a stretched string all multiples of frequencies can be obtained i.e., if fundamental frequency is n then higher frequencies will be 2n, 3n, 4n ...
So, the difference between any two successive frequencies will be 'n'
According to question, n = 420 Ã¢ÂÂ 315 = 105Hz
So the lowest frequency of the string is 105 Hz.

Answer

10.5 Hz

Answer

105 Hz

Answer

155 Hz

Answer

205 Hz

Waves

A string is stretched between fixed points separated by 75.0 cm. It is observed to have resonant frequencies of 420 Hz and 315 Hz. There are no other resonant frequencies between these two. The lowest resonant frequency for this string is

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