Light that enters the new medium <em>perpendicular to the surface</em> keeps sailing straight through the new medium unrefracted (in the same direction).
Perpendicular to the surface is the "normal" to the surface. So the angle of incidence (angle between the laser and the normal) is zero, and the law of refraction (just like the law of reflection) predicts an angle of zero between the normal and the refracted (or the reflected) beam.
Moral of the story: If you want your laser to keep going in the same direction after it enters the water, or to bounce back in the same direction it came from when it hits the mirror, then shoot it <em>straight on</em> to the surface, perpendicular to it.
This question involves the concepts of the law of conservation of energy and kinetic energy.
The girl's fastest speed is "3.7 m/s".
According to the law of conservation of energy, the girl will have the fastest speed at mean position, which will be calculated as follows:
Loss in Potential Energy = Gain in Kinetic Energy

where,
v = maximum speed = ?
g = acceleration due to gravity = 9.81 m/s²
Δh = change in height = 1.3 m - 0.6 m = 0.7 m
Therefore,

<u>v = 3.7 m/s</u>
<u></u>
Learn more about the Law of Conservation of Energy here:
brainly.com/question/381281?referrer=searchResults
Answer:
The sound level will be 1.870 dB louder.
Explanation:
Given that,
Power = 130 W
Power = 200 W
We need to calculate the sound level
Using formula of sound level

For one amplifier,
...(I)
For other amplifier,
...(II)
For difference in dB levels




Hence, The sound level will be 1.870 dB louder.
39.6832 pounds would be your answer
Answer:
Object A will get 200 & object B will get 400 Potential Energy
Explanation:
Potential Energy = mgh (mass x gravity x height)
For Object A :-
2 (mass) x 10 (approx gravity on Earth) x 10 (distance/height)
= 200
For Object B :-
4 x 10 x 10
= 400
Hence Object B will have High Potential Force than A.
Hope it helps. Thanks