Gravitational Force of Earth: Overview, Questions, Preparation

The force that acts in the universe to attract the objects towards itself is known as Gravitational force. In other words, it is the relationship between the two masses. One of the masses is heavier and is termed as the "source mass" while the other is the lighter one known as the “test mass”.

It can be written as:

F (r) = f (r) r^

It shows us the relations of two masses and the relativistic effects that are associated with it.

Newton's law of gravitation is used to describe the gravitational force. It is used to determine the mass of the objects and the distance between the ball when it is thrown to the ground.

The formula of the gravitational force is written as:

F = Gm₁m₂ / r²

Here, the m1 and the m2 are the masses of the body, lighter and heavier, both of which are measured in kg.

The universal gravitational constant is denoted by G. The gravitational constant is 6.674 x 10^-11 Nm²kg².

The gravitational force between two objects is denoted as F; it is measured in Newton (N)

The separation is denoted as r and is measured in kilometre (km).

On earth, the acceleration due to gravity is 9.8 m/s². It is determined by the mass of the earth and the radius of the earth. It also means that the velocity of an object falling will increase the acceleration by 9.8 every second. This acceleration occurs because of gravity on the earth.

Calculation of Acceleration due to gravity on Earth

The formula to calculate the acceleration due to gravity is g = GM / R²

Here, the gravitational constant is denoted as G,

The value of G is 6.674×10^-11m³kg^-1s^-2.

Mass is denoted as M,

Radius as R, and acceleration due to gravity as g.

Mass of the earth = 6 × 10²⁴

Radius = 6.4 × 10⁶

By putting these values in the formula, we get,

g= 6.67 × 10^-11 × 6 × 10²⁴ / (6.4 × 10⁶)²

So, the acceleration due to gravity on earth is 9.8 m/s^2.

The Gravitational Force of Earth for Class 11

The chapter 'Gravitation' Holds a weightage of only 4 marks. It includes 2 questions, consisting of one objective type question of 1 mark and one short question of 3 marks, making a total of 4 marks.

Example 1: Write the value of acceleration due to gravity on earth.

Answer: By solving the equation g= 6.67 × 10^-11 × 6 × 10²⁴ / (6.4 × 10⁶)²

We will get the exact acceleration due to gravity, i.e., 9.8 m/s²

Example 2: Write the formula to calculate the acceleration due to gravity.

Answer: The formula to calculate the acceleration due to gravity is g = GM / R²

Example 3: Write the example of gravity.

Answer: The force between earth and the sun, the force holding all the gases in the sun; all are examples of gravitational energy.

Q: What is the gravitational force?

Q: What do you mean by the acceleration due to gravity?

Q: What is the value of G?

Q: What is the formula of gravitational force?

Q: Why is the potential gravitational energy is negative?