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 .
The two check-marks in the picture are in the correct places.
Answer:
Different elements all have different amounts of electrons in there outter shell.
Explanation
If you look at a periodic table, the elements are all listed in "Groups" up at the top you'll see the numbers, or columns. Each column's number represent how many electrons there are in each particular element.
hope this makes sense....
Answer:
Explanation:
Time to mow 1 lawn by Wilma is 80 minutes
so work done in 1 minute by Wilma is given as
Similarly Rocky mow same lawn in 120 minute
so work done in 1 minute by Rocky is given as
now we know that they both worked by "t" time
so total work performed by them
they both mow 2 lawns then it is given as
Answer:
The correct option is A
Explanation:
Buoyancy can be described as the upward force that causes an object to float on water. <u>When the buoyant force of a liquid is greater than the weight of an object, the object will move to the surface of the liquid and float (because the buoyant force would be able to push it upwards)</u>. If the buoyant force is lesser than the weight of the object, the object will sink (because the buoyant force would not be able to push the object upwards). And when the buoyant force and weight of an object cancel out, the object would be suspended at the depth that this occurs.
Thus, from the explanation above, it can be deduced that for an object to float, buoyant force must be greater than weight of the object. Thus, the correct option is A.