Answer:
Explanation:
Because we assume the pendulum is a "mathematical pendulum" (neglecting the moment of inertia of the bob), we can find:

By using the 
The mean position is the position when <em>y</em> = 0, so:
rad/s
and
in centimeters (cm).
As we know that gravitational force of Sun will provide the centripetal force to all planets
so here we will have


here we know that



now from above equation




In water, it's drag. Exactly the same as air resistance
only hundreds of times greater.
Imagine you are in a swimming pool 30m deep. Assuming you know that water is denser than air, you would know that the 30m of water above you will carry more weight, and press down on your body. Say you were in a swimming pool 60m deep, you would be sandwiched between 30m of water pressing down on you, and the upthrust created by the 30m of water below you.
In a building 30m up, the pressure will be regulated, as you are in a building. The floor will be strong enough to support the weight of the body, and the body will not recoil into itself.