An airplane is traveling at 400 mi/h. It touches down at an airport 2000 miles away. How long was the airplane airborne?

5 hours

Explanation:

Given that

Speed of the airplane, v = 400 mile/hr

Distance of the airport, s = 2000 miles

This is quite a straightforward question that deals with one of the basic formulas in physics.

Speed.

speed is said to the the ratio of distance covered with respect to the time taken. This can be mathematically expressed as

Speed, v = distance covered, d / time taken, t

v = d / t

In the question above, we're looking for the time taken. So, so make t, subject of formula.

t = d / v, now we proceed to substituting the earlier given values into this equation.

t = 2000 / 400

t = 5 hrs,

therefore we can conclude that the airplane was airborne for 5 hours

answer: a) y=-8x+5

a) m= -8

b) m= -2

c) m= 7

d) m= 6

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.