High School

Two violin strings are tuned to the same frequency, 294 Hz. The tension in one string is then decreased by 2.5%. What is the new frequency of the string?

Answer :

The new frequency of the violin string after the tension is decreased by a factor of 2.5 is roughly 186 Hz, calculated by using the relationship between tension and frequency for a string fixed at both ends.

The frequency of a string fixed at both ends, like a violin string, is determined by the string's length, tension, and mass per unit length.

When the tension in a violin string tuned to a frequency of 294 Hz is reduced, the new frequency can be found by using the properties of wave motion.

The equation for the frequency f of a string is given by: f = (1/2L) * sqrt(T/μ), where L is the length, T is the tension, and μ is the mass per unit length.

The frequency is directly proportional to the square root of the tension.

If the tension is decreased by a factor of 2.5, the new tension T' is T/2.5. We can calculate the new frequency f' using the following steps:

  1. Determine the initial tension (which is not necessary for the calculation as we are looking for a ratio).
  2. Apply the change in tension: T' = T/2.5.
  3. Calculate the square root of the tension ratio: sqrt(T'/T) = sqrt(1/2.5).
  4. Calculate the new frequency: f' = f * sqrt(T'/T).

Carrying out the calculation:

  • sqrt(1/2.5) ≈ 0.6325
  • f' = 294 Hz * 0.6325 ≈ 186 Hz

Therefore, the new frequency of the string is 186 Hz.