Answer:
Explanation:
The problem is based on interference in thin films
refractive index of water is more than given oil so there will be phase change of π at upper and lower layer of the film .
a )
for constructive interference , the condition is
2μt = nλ where t is thickness of layer , μ is refractive index , λ is wavelength and n is order of the fringe
Putting the values
2 x 1.27 t = n x 640
2 x 1.27 t = 640 ( for minimum thickness n = 1 )
t = 252 nm .
b )
2 x 1.27 t = m₁ λ₁
for destructive interference
2μt = (2m₂+1)λ₂/2
2 x 1.27 t =(2m₂+1)λ₂/2
m₁ λ₁ = (2m₂+1)λ₂/2
2m₁λ₁ = (2m₂+1)λ₂
2m₁ / (2m₂+1) = λ₂ / λ₁
2m₁ / (2m₂+1) = 548/ 640
2m₁ / (2m₂+1) = .85625
2m₁ = .85625 (2m₂+1)
This is the required relation between m₁ and m₂
Answer:
Explanation: Where do the photons in the cosmic background radiation originate? mostly from the Big Bang with a small contribution from stellar nucleosynthesis. the density of ordinary (baryonic) matter in the universe. How were the cosmic background photons emitted?
Answer:
earth
Explanation:
The formula for the orbital period of the moon is given by
As the time period is inversely proportional to the square root of the acceleration due to gravity of the planet.
As the value of acceleration due to gravity on Jupiter is more than the earth, so the period of moon around the earth is large as compared to the period of the moon around the Jupiter when the distance is same.
Answer:
4.44s
Explanation:
A 34-kg child on an 18-kg swing set swings back and forth through small angles. If the length of the very light supporting cables for the swing is 4.9 m, how long does it take for each complete back-and-forth swing? Assume that the child and swing set are very small compared to the length of the cables
since the mass of the child and that of the swing is negligible, the masses wont be involved in the calculation
T=2π√L/g
g=acceleration due to gravity which is 9.81m/s2
the length of the supporting cable is 4.9m
T the period
period is the time required to make a complete oscillation
T=2*π√4.9/9.81
T=2*π*0.706
T=4.44s
4.44s