Suppose you have a glider and a hanging mass that you wish to know the masses of but you do not have a triple-beam balance available. You set up an experiment like that done in Lab 4: Newton's Second Law, in which a glider moves across an essentially frictionless airtrack, pulled by a light string which passes over a pulley and connects to a hanging mass. You take the following data: H = 75.0 cm t = 1.8 s Where H is the distance the hanging mass falls and t is the time it takes to fall (t has been averaged over five trials). Using methods similar to those in Lab 4, determine which of the following could be the masses of the glider (m1) and the hanging mass (m2).

the choice of a glider to hanging mass is a ratio of 20.2

Explanation:

The Newton´s second law for glider is:

Fnet=Ma

T=Ma

The Newton´s second law for hanging mass is:

Fnet=ma

mag-T=ma

Replacing:

mag-Ma=ma (eq. 1)

Clearing a:

a=(mg)/(m+M)

The expression for motion is:

Clearing a:

Replacing values:

From eq. 1:

M/m=20.2

b would be the answer

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.