You can painlessly wade into a pool, but doing a belly flop off of the high diving board hurts because of

You can painlessly wade into a pool, but doing a belly flop off of the high diving board hurts because of the cohesion of the water molecules.

Explanation:

Water is represented as H20 where two hydrogen atoms are bonded to one oxygen atom. Due to force of attraction between the water molecules they stick together providing a greater force when an object or a body acts upon them.

Hence moving slowly in water or dipping slowly will not produce any opposite form whereas flipping does as it tries to separate the body between the water molecules when we fall with a certain amount of force.

vapour or gas assuming atmospheriv pressure

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.