Anna drew a diagram to compare the strong and weak force
Strong
Weak
Which labels belong in the areas marked X, Y, and Z?
O X: infinite range
Y attractive and repulsive
Z very small range
X: attractive only
Y very small range
Z attractive and repulsive
O X: attractive and repulsive
Y: infinite range
Z: attractive only
O X: very small range
Y: attractive only
Z infinite range
х
Y
N

you would expect a sound wave to speed up. - b)

the displacement produced by the body.  

the amount of force subjected to the body.  

the angle between the direction of force and displacement

d) physical means can be used to separate the components of air.

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.