Question

What type of force is present in the formation of tides?

Answer 1

Hint: Tides are often formed in large oceans and lakes where its depth is more and these tides tend to be periodic in nature. The concept and cause of tides needs to be probed upon in order to find the answer to the question. The factors that can possibly affect the water on the Earth’s surface are considered. The concept of gravity and its pull needs to be applied in order to find the force that causes the formation of tides.

Complete answer:
The above problem revolves around the concept of tides and the cause of it. In order to find the type of force that forms these tides we first need to know what tides are and why they ae formed.Tides are the rise and fall of waves in an ocean or sea where the water level tends to rise by a certain amount above its surface. The waves that we see in our day to day life in large oceans and seas that tend to rise to a level are basically known as tides where the crest of the wave, that is, when the wave reaches its highest point then it is known as high tide and the trough of the raised wave which is its lowest point is known as low tide.

Let us now come to the cause of these tides, that is, why these tides are formed in oceans. The tides are formed due to the gravitational force exerted by the Sun and Moon on the Earth’s surface where the water resides. When the water level of an ocean or a sea is aligned with that of the Sun or moon then the tides are formed. Thus gravity is the reason for the tidal waves being formed in the sea.

Now, we come to the reason behind the formation of these tides. Anything which has a mass will exert a gravitational force on another body and this is the force of attraction due to which they try to move towards each other. The force of gravity is why the water is present on the surface of the Earth. This gravitational force is said to be given by a formula that was determined experimentally. This formula is as follows:
$F = \dfrac{{G{m_1}{m_2}}}{{{r^2}}}$

As per the above formula we can see that the gravitational force is inversely related to the distance between two bodies with some amount of mass. Since the Sun is present at a farther distance from Earth compared to that of the Moon, the tides and its corresponding gravitational pull is mostly due to the Moon.

The waves tend to rise in the direction of the moon due to gravity which pulls the bodies, that is, the water on the Earth’s surface and the Moon towards each other and hence a bulging of the water’s surface as it tries to move towards the Moon which is present directly above its surface and hence there is a sudden rise in the water level leading to formation of tides.

Hence, gravity is one of the main causes for formation of tides and hence the force that is present in the formation of tides is the gravitational force. Other reasons or causes can be due to the centrifugal force of the Earth which is produced since the Earth rotates about its axis which affects the water levels in seas and oceans

Note: It is said that not only the moon but the Sun is also responsible for the gravitational pull of the waves of the ocean. Even though we have discussed the formation of tides mostly due to the moon in the solution to the question, the sun also to an extent is responsible for exerting gravitational force towards Earth and hence the tide formed due to the Sun is known as solar tide.