Physical fitness involves the proper functioning of which body systems?

select all that apply.
auditory
circulatory
respiratory
integumentary
muscular
reproductive

circulatory

respiratory

muscular

Explanation:

The physical fitness can be define as the state of well being and health. It indicates towards the ability of the organisms to perform various aspects of physical activities such as sports, daily routine work, and occupational tasks. It is achieved by moderate to vigorous physical exercises, sufficient amount of rests and proper nutrition.

The physical fitness involves the proper functioning of the vital systems of the body these includes the respiratory, circulatory and muscular. As the body performs exercise it requires more amount of oxygen also the muscles performing activity deprive of the oxygen, the rate of respiration increases, more amount of blood is pumped out by the heart to fulfill the need of oxygen.

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.