Answer:
Explanation:
In case of oil slick a thin layer of oil is formed on water . This thin layer creates a rainbow of colour . The phenomenon is due to interference of light waves , one reflected from the upper surface of oil and the other reflected from the lower surface of the oil.
For formation of bright colour
2 μ t = ( 2n + 1 ) λ / 2
μ is refractive index of oil , t is thickness of oil layer λ is wave length of light falling on the layer .
given μ = 1.2 , λ = 750 x 10⁻⁹ ,
2 x 1.2 t = ( 2n + 1 ) 750 x 10⁻⁹ / 2
For minimum thickness n = 0
2.4 t = 375 x 10⁻⁹
t = 156.25 n m
B ) If the refractive index of layer of medium below oil is less than that of oil , the condition of formation of colour changes
The new condition is
2 μ t = n λ
2 x 1.5 t = 750 nm , n = 1 for minimum wavelength .
t = 250 nm
C ) Light mostly transmitted means dark spot is formed at that point .
For that to be observed from water side , the condition is
2 μ t = ( 2n + 1 ) λ / 2
λ = 4μ t / ( 2n + 1 )
For maximum wavelength n = 0
λ = 4μ t
= 4 x 1.5 x 200 nm
= 1200 nm .
Answer:
The time is 1.8s
Explanation:
The ball droped, will freely fall under gravity.
Hence we use free fall formula to calculate the time by the ball to hit the ground
Where h is the height from which the ball is droped, g is the acceleration due to gravity that acted on the ball, and t is the time taken by the ball to hit the ground.
From the question,
h=16m
Also, let take
By substitution we obtain,
Diving through by 9.8
square root both sides, we obtain
D bc thats sound like the only resonable answer
