The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:

**Gravitation** is the force of the interplay between two masses. There are two types of masses – source mass and test mass. Of the two, the heavier one is termed source mass, and the lighter one is termed test mass. Gravitational force is a focal power, which relies upon the situation of test mass from the source mass and consistently acts along the line joining the focuses of the two masses. So, understanding the concepts of gravitation can assist you in other concepts of physics.

This law was postulated by sir Isaac Newton. **Newton’s law of gravitation **puts forth the philosophy that explains the motions of planets and moons. This law is also called the universal law of gravitation.

The following is the equation for universal gravitation:-

where F is the gravitational power acting between two forces, m1 and m2 are the two masses, r is the separation between the focuses of their masses, and G is the gravitational constant.

**Kepler’s laws of planetary motion** explain how the planets revolve around the sun. It has three laws –

**1. Law of orbits **– It states that planets revolve around the sun in orbit as foci. When a planet is closer to the earth, it is called perihelion, and when against the earth, it is called aphelion.

**2. Law of equal areas **– It explains that no matter where the orbit is located, each planet covers the same area of space and in the same interval of time.

**3. Law of periods **– The square of the period of an insurgency of a planet around the sun in a curved circle is straightforwardly proportional to the block of its semi-significant axis.

**Acceleration due to gravity** is the quickening picked up by an object because of gravitational power. Its SI unit is m/s2. It has both size and course; thus, it’s a vector amount. **Acceleration due to gravity** is expressed by g. You need to apprehend that the standard estimation of g on the outside of the earth, a drift level is 9.8 m/s2. The formula of acceleration due to gravity is, g = GM/r2 , where G is the universal gravitational constant, M is mass, and r is the radius.

**Variation of acceleration due to gravity** can take place in the following cases –

- Height from the surface of the earth
- Depth below the surface of the earth
- The shape of the earth
- The rotation of the earth

When source mass and test mass correlate due to the force of gravitational attraction, it is called the **gravitational field.** This model explains when a body is surrounded by space in which other bodies experience the force of gravity. It is useful in the study of gravitational force. Newton’s per kilogram measures the gravitational field.

Formula:

g = F/m

Where

F = gravitational force and m = mass of the object.

**Intensity of gravitational field**

The strength of the gravitational field is called gravitational field intensity. **The intensity of the gravitational field is (Eg) = – GM/r2 ***r*^. Gravitational field intensity relies on source mass.

**Gravitational potential energy **

Energy procured by an object due to the change in the position of the object in the gravitational field, it is called **gravitational potential energy**. In other words, it is an energy associated with gravity.

For example, if you put an object on the chair and other objects above the chair. So it is stated that the object placed above the chair will have more **gravitational potential energy** than the other.

Formula: GPE = m⋅g⋅h

Where

m- The mass in kilograms,

g – Acceleration due to gravity

h – The height above the ground

**Escape velocity** can be defined as the minimum speed at which an object goes to break free from either the planets or moon’s gravity and leave with no headway of impulse.

Where

- vc is the escape velocity
- G is the universal gravitational constant
- M is the mass of the celestial object
- r is the distance from the object to the centre of mass

**What is the cause of gravitation?****What is the force of gravity on earth?****What is the definition of gravitation?**

The moon goes around the earth, and the sun revolves around the earth is all due to the force of gravity. Gravitation is a paramount topic in physics of utmost importance. Understanding the subject matter of gravitation is a prerequisite to understanding the various laws of gravity. For better comprehension of the topic, you can watch the videos on MSVgo app and official site. It has a video library that explains concepts with examples or explanatory visualisations or animations. MSVgo is developed that imparts a detailed explanation of any complex topics or concepts. Check the videos and enhance your knowledge with MSVgo!

- Physical World
- Units and Measurements
- Motion in a Straight Line
- Motion in a Plane
- Laws of Motion
- Work, Energy and Power
- System of Particles and Rotational Motion
- Mechanical Properties of Solids
- Mechanical Properties of Fluids
- Thermal Properties of Matter
- Thermodynamics
- Kinetic Theory
- Oscillations
- Waves