Two satellites in space with a mass of 2000kg, are 1500m apart from each other. What is the force gravity between them?

F = 1.185 x 10⁻¹⁰ N

Explanation:

The force of gravitation between two objects is given by Newton's Law of Gravitation. According to this law:

where,

F = Gravitational Force between satellites = ?

G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ Nm²/kg²

m₁ = m₂ = mass of each satellite = 2000 kg

r = distance between both satellites = 1500 m

Therefore,

F = 1.185 x 10⁻¹⁰ N

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.

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide