Which tool is a wheel and axle? a screw cap a seesaw an axe a windmill

A windmill.

Explanation:

A mechanical device which consist a grooved wheel which is turned by the chord or chain which is attached through axle with a supporting standard.

It consists a hinge or a bearing which support the axle and help in rotation.

There are the few examples of the wheels and axles are bicycle tire, fans, a windmill etc.

In the given problem seesaw does not contain wheel, an axe does not contain wheel and screw does not contain axle.

Therefore a windmill is a tool which is of wheel and axle.  

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.

hi,

what occurs during a solar eclipse?

there are small tides across earth.

the moon is between earth and the sun.

p.s. im not sure if the first answer is correct because during a solar ecliphse there are spring tides and i dont know if they are the same.