An object starts from rest an accelerates at a constant rate in the +x direction and at some magnitude of velocity, in the +x direction, it has covered a displacement of 19 meters in the +x direction in a time of 2.6 seconds. a different object starts from rest and accelerates at a constant rate in the -x direction with a magnitude of acceleration equal to a factor 4 times less than the first object. when the second object reaches a magnitude of velocity which is a factor of 3 larger than the first objects, was is the magnitude of the second object's average velocity in m/s?

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.

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle