Hydrostatic balance and lapse rate for air subject to gravity: assume that the atmosphere has a uniform composition, with molecules having mass m, and that it can be treated as an ideal gas. also assume that the acceleration of gravity can be treated as independent of height. (a) for a small volume of air at equilibrium, of height dz, a vertical difference in pressure on the top and bottom face provides a supporting force to balance the weight of the gas within the volume. based on this idea, derive a relation for dp/dz, showing that it is proportional to p/t (b) the temperature variation with height is established for the most part by convection which proceeds adiabatically. starting with the first law, for an adiabatic process, consider the vertical displacement of a quantity of air, and find a relation between du and pdv for the gas in this process. replace du with a corresponding relation using c, and use the ideal gas law to express dv in terms of dp and dt. as a result, find an expression for dt/dp. finally, use your result from part (a) to obtain an expression for dt/dz, and show that the result is dt/dz -mg/cp.

a.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid

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.

cant without the picture! ?

0.93xc=0.93x3x10^8m/s

2.54cm is 1 inch

360seconds i 1 hr