Answer:
<em>D. refraction</em>
Explanation:
Refraction: Refraction is change in direction of light rays. Refraction occurs whenever light rays travels from a transparent medium to another transparent medium of different density. The abrupt change in direction at the surface of the surface of the two media is referred to as <em>refraction</em><em>.</em>
<em>Refraction occurs when light travels from air to glass or from air to liquid.</em>
<em>Laws Of Refraction:</em>
(i) The incident ray, the refracted ray and the normal, all at the point of incident lies in the same plane.
(ii) The ratio of the sine of the angle of incident to the sine of the angle of refraction is a constant for a given pair of media.
<em>Thus the right option is D. refraction</em>
Answer: 200 N/m
Explanation:
The Gravitational spring energy(Us) is equal to 1/2kx^2. So we have x as .2 m and Us as 4 N. So 4 N = 1/2 * k * .2^2. So now we solve for K and get 200 N/m.
i thinkits an instrument called seismograph. not sure
Wind speed and air temperature are used to calculate a windchill factor.
<u>Explanation:</u>
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Wind-chill factor is the reduction of body temperature due to the passing flow of lower-temperature air.
The air temperature value is always higher than the wind chill numbers. the heat index will be used if the apparent temperature is higher than the air temperature.So, Wind speed and air temperature are mainly used to calculate a windchill factor.
There are many ways, the surface loses its heat through conduction, evaporation,radiation, and convection.The rate of convection depends on the difference in temperature between the surface and the fluid surrounding the surface and the velocity of that fluid with respect to the surface. The air around the warm surface will be heated, an insulating layer of warm air forms against the surface.The layer becomes a boundary between two. As the wind speed is high the surface cools down rapidly.
F = m*a, mass times acceleration.
F = 15*10 = 150 N