Explanation:
Since, it is given that one hand completes 3.19 vibrations in 8.46 sec. Therefore, in one second the number of vibrations will be as follows.
= 0.377 vibrations
Hence, frequency (f) = 0.38 Hz
Now, formula to calculate the speed is as follows.
v =
or,
=
= 1.57 cm
Thus, we can conclude that the wavelength is 1.57 cm.
The number of lines per mm in the diffraction grating is 326.
<h3>What is diffraction grating?</h3>A diffraction grating is a type of optical instrument obtained with a continuous pattern. The pattern of the diffracted light by a grating depends on the structure and number of elements present.
The given data in the problem is
is the angle formed between the path of the incident light and the diffracted light = 9. 2°
λ is the wavelength of the light=490nm=4.9
N is the number of lines per mm in the diffraction grating=?
n is ordered = 1
The formula for the diffraction grating is;
The number of lines per mm is found as;
Hence the number of lines per mm in the diffraction grating is 326.
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