Answer:
Its speed decreases.
Explanation:
When light enters into water, its speed decreases (as well as its frequency). This is the reason why refraction (the bending of light when it changes media) occurs.
This can be proven mathematically.
Given that the refractive index of water is 4/3, we know that refractive index is the ratio of the speed of light in a vacuum to the speed of light in another medium.
Therefore,
4/3 = (speed of light in vacuum) / (speed of light in water)
Speed of light in a vacuum is 3 * 10^8. Hence,
Speed of light in water is:
v = (3 * 10^8) / (4/3)
v = 2.25 * 10^8 m/s
As we can see, the speed of light decreases in water.
Answer:
The two waves will add vectorially to produce a small amplitude wave in a valley phase.
Explanation:
The two waves will add vectorially to produce a small amplitude wave in a valley phase. This is because the amplitudes of the waves are slightly different and in opposite directions. When wave 1 cancels out all of wave 2, the resultant wave would be the slight difference between both waves, and it would be in the direction of wave 1 which is a valley phase.
A) To obtain an inverted image of an object of same size a convex lens is used.
B)
In this question we have given
Distance between candle flame and screen=4
it means distance between candle flame and lens +distance between lens and screen =4m
u+v= 4m
u= v
therefore, 2u= 4m
or, u=-2m ( u is taken negative because it lies on left side of the lens)
and v=2m
we have to find the focal length of convex lens
Hence, Focal length of the lens is 1m
and lens should be placed at a distance of 2m from the flame
Answer:
Time - taken = 2.5 s
deceleration= -8 m/s²
Solution:
Given:
speed, v = 8 m/s
distance, d = 20m
To Find:
deacceleration = ?
As we know speed is defined as
v = d/t
plugging in the values
t = 20/ 8
t = 2.5s
Now from deceleration formula
a = - v/ t
a = - 20/ 2.5
a = - 8 m/s²
Thus, the time taken and acceleration is 2.5 s and -8 m/s²
respectively.
Learn more about deceleration here:
brainly.com/question/13354629
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