In action comics #1 (1938), superman could "leap tall buildings in a single bound." initially, superman was said to have come from a planet with a larger gravity than earth's gravity and that was the sole source of his "powers". based on this premise and the fact that in 1938 a tall building was about 40 stories (122 meters), let's try to answer the following questions about superman's leaping of tall buildings: a. how long would he be in the air? b. how fast would superman be by launching himself off the ground? c. what acceleration would he have to produce to achieve this launch speed?

a) 9.96 seconds

b) 48.92 m/s

c) 48.92 m/s²

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration due to gravity = 9.81 m/s²

The speed at which Superman launches himself is 48.92 m/s

An object which is thrown at an initial velocity when it reaches the same point from where it was thrown it achieves the same initial velocity

Time to come down is 4.98 seconds

Total time Superman will be in the air is 4.98+4.98 seconds = 9.96 seconds

Here, the time taken to accelerate to his initial speed is not given. It can be assumed that it is almost instantaneous. The time may be infinitesimally small. So, the acceleration might be almost 48.92 m/s²

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.