A block is placed at the bottom of an incline. Its connected by a string that is running through a pulley, a second mass which hangs vertically at the top of the incline. The mass at the bottom is 3kg, and the mass hanging at the top is 5kg.
The incline is at angle of 20 . There is a coefficient of kinetic friction
between the incline and the first block of 0.13. The base of the incline is 10m long. The system is released from rest.

1. Draw free body diagrams for both blocks at the moment of release
2. Calculate the tension and acceleration of the system
3. How fast is the hanging block moving just before it strikes the ground

d. air pressure decreases as altitude increases.

do you have a formula possibly

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.