The meter was originally defined so that the period of a meter-long simple pendulum would be exactly 2.00 second. (Was your measured value close to this?) Given the relationship, T^2 alpha L (T^2 is proportional to L) what would be the length of a simple pendulum, in centimeters, with a period of exactly one second?

Explanation:

Given that,

Initial length of simple pendulum,

Initial time period,

We need to find the length of the simple pendulum when the period is exactly 1 second.

We know that the time period of simple pendulum is given by :

Put all values and find L₂

So, the length of the pendulum with a period of exactly one second is 25 cm.

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.

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.