Answer:
39.05°
Explanation:
As we know that, the diffraction is the phenomena of bending of light when it passes through an obstacle.
Mathematically,
Here, d is slit width, is the wavelength, n is the order,
is the angle.
Given that, d is 84 cm, n is 2, and the wavelength can be calculated as,
Here, c is the speed of sound and f is the frequency of sound wave.
Here, c is 343 m/s and f is 1300 Hz,
Therefore,
Recall diffraction equation in term of .
Put all the variables.
Therefore, it is the required angle between the first 2 order of diffraction.