<span>I think that the coefficient of cubical expansion of a substance depends on THE CHANGE IN VOLUME.
Cubical expansion, also known as, volumetric expansion has the following formula:
</span>Δ V = β V₁ ΔT
V₁ = initial volume of the body
ΔT = change in temperature of the body
β = coefficient of volumetric expansion.
β is defined as the <span>increase in volume per unit original volume per Kelvin rise in temperature.
</span>
With the above definition, it is safe to assume that the <span>coefficient of cubical expansion of a substance depends on the change in volume, which also changes in response to the change in temperature. </span>
The Beams And Joints That Hold It .
Answer
given,
wavelength (λ)= 500 n m
thickness of film= 10⁻⁴ cm
refractive index = μ = 1.375
distance traveled is double which is equal to 2 x 10⁻⁴ cm
a) Number of wave


N = 2.91
N = 3
b) phase difference is equal to
Reflection from the first surface has a 180° (½λ) phase change.
There is no phase change for the 2nd surface reflection and there is no phase difference for the 2nd wave having traveled an exact whole number of waves.
net phase difference = 
= 270°
B is the answer you need and i honestly got this question on a middle school test
you must be in different area then me