1. Frequency: 
The frequency of a light wave is given by:

where
is the speed of light
is the wavelength of the wave
In this problem, we have light with wavelength

Substituting into the equation, we find the frequency:

2. Period: 
The period of a wave is equal to the reciprocal of the frequency:

The frequency of this light wave is
(found in the previous exercise), so the period is:

Answer:
Explanation:
Giant impact has resulted into formation of celestial bodies such as moon.
Moon was formed years after the Earth was formed. When Earth collided with very big size bodies, there was vaporization of chunks of the planets in to the space. Gravity plays its role and bounded those particles together thus forming moon.
This formation explains Moon is made up of lighter elements and contains too little iron where as Mercury was formed with the rest of the planets and just like earth, its core is formed first which is of iron and then collected the lighter elements to form crust and mantle.
Though both Moon and Mercury were the result of giant impacts yet they have different elements because mercury was made earlier and its is closer to moon hence it collected heavy elements such as iron to for the formation where as moon is the result of collision of Earth and other Mars- sized body hence its constituent particles are different that of mercury.
To solve this problem it is necessary to apply the concepts related to the Rotational Force described from the equilibrium and Newton's second law.
When there is equilibrium, the Force generated by the tension is equivalent to the Force of the Weight. However in rotation, the Weight must be equivalent to the Centrifugal Force and the tension, in other words:

Where
Angular velocity is equal to the Period, at this case Earth's period
Radius of the Earth
m = mass
= Force of Tension
Newton's second law
Replacing and re-arrange to find the Tension we have,






Therefore when Sneezy is on the equator he is in a circular orbit with a Force of tension of 503.26N
In most calendar years there are two lunar eclipses; in some years one or three or none occur. Solar eclipses occur two to five times a year, five being exceptional
your answer is c) Ends
As can be visualized with the magnetic field lines, the magnetic field is strongest inside the magnetic material. The strongest external magnetic fields are near the poles. A magnetic north pole will attract the south pole of another magnet, and repel a north pole.