Answer:
The speed of light changes as it moves between media. This causes refraction. Angles of refraction can be calculated using known speeds or wavelengths. Beyond the critical angle, light is reflected.
Answer:
F = 2520 N
Explanation:
We have,
The maximum acceleration of a fist in a karate punch is 4200 m/s². The mass of the fist is 0.6 kg.
It is required to find the force that the wood place on the fist. Force is given by the product of mass and its acceleration such that,
F = ma

So, the force of 2520 N is acting on the wood.
v = x/t
v = average velocity, x = displacement, t = elapsed time
Given values:
x = 6km south, t = 60min
Plug in and solve for v:
v = 6/60
v = 0.1km/min south
Stairs don't have any power at all. All the energy used to climb them
has to come from your muscles.
An elevator gets its power from the electric motors that lift it. All YOU
have to do is stand there and look around.
All of this is a big part of the reason why elevators have become so
popular, and why no buildings with more than a few floors were built
before elevators were invented.
D. According to the hierarchy of needs the body and mind must be taken care of first and foremost.