You are camping in a tent, you have some very hot water (700C) in a water bladder, but you realize thatin fact you do not have enough drinking water. Your plan is to melt the block of ice you have seen infront of your tent using the boiling water you have and then treat the entire quantity. You estimate thatthe ice block has about 1 kg and is at a temperature of about -200C. How much water do you need tomelt the ice and rise its temperature to 50C

a longitudinal wave moves energy that is to the direction of the wave’s movement. - true

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

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.