A 2.00 m long string transmits waves at [tex]$12.9 \, \text{m/s}$[/tex].

At what frequency will it create standing waves with 3.00 loops?

[tex]f = [\text{?}] \, \text{Hz}[/tex]



Answer :

To determine the frequency at which a 2.00-meter-long string will create standing waves with 3.00 loops, given that the wave speed is [tex]\(12.9 \, \text{m/s}\)[/tex], follow these steps:

### Step 1: Calculate the Wavelength

First, understand that for standing waves, the relationship between the string length [tex]\( L \)[/tex], the number of loops (or antinodes) [tex]\( n \)[/tex], and the wavelength [tex]\( \lambda \)[/tex] is given by:

[tex]\[ \lambda = \frac{2L}{n} \][/tex]

where [tex]\( L \)[/tex] is the length of the string and [tex]\( n \)[/tex] is the number of loops.

Given:
- Length of the string, [tex]\( L = 2.00 \, \text{m} \)[/tex]
- Number of loops, [tex]\( n = 3.00 \)[/tex]

Plug in the values to find the wavelength:

[tex]\[ \lambda = \frac{2 \times 2.00 \, \text{m}}{3.00} = \frac{4.00 \, \text{m}}{3.00} = 1.3333 \, \text{m} \][/tex]

So, the wavelength [tex]\( \lambda \)[/tex] is approximately [tex]\( 1.3333 \, \text{m} \)[/tex].

### Step 2: Calculate the Frequency

The frequency [tex]\( f \)[/tex] of the wave is related to the wave speed [tex]\( v \)[/tex] and the wavelength [tex]\( \lambda \)[/tex] by the equation:

[tex]\[ f = \frac{v}{\lambda} \][/tex]

Given:
- Wave speed, [tex]\( v = 12.9 \, \text{m/s} \)[/tex]
- Wavelength, [tex]\( \lambda = 1.3333 \, \text{m} \)[/tex]

Using these values to find the frequency:

[tex]\[ f = \frac{12.9 \, \text{m/s}}{1.3333 \, \text{m}} \approx 9.675 \, \text{Hz} \][/tex]

Therefore, the frequency at which the string will create standing waves with 3.00 loops is approximately [tex]\( 9.675 \, \text{Hz} \)[/tex].