## Gravity Formula

Everything you need to know about Gravity Formula is provided below. Please continue reading the entire document carefully to fully understand the topic.

In physics, gravity is the basic interaction that leads to mutual attractions between all objects of masses or energy.

Gravity, also referred to as gravitation, is the force that exists among all material things in the universe. In any two objects or units of non-zero weight, the force of gravity tends to pull against each other.

Newton’s Universal Gravitation Act states:

**“Every particle attracts all other particles in the universe with an equal force directly with mass production and in proportion to the square of the distance between them”.**

However, gravity is the most important interaction between objects on a massive scale, and it determines the movement of planets, stars, galaxies, and even light.

## Formula

If two masses m_{1} and m_{2} are kept at a distance r from each other, the gravity formula is calculated as;

**F = Gm _{1}m_{2} / r^{2}**

where,

F = force due to gravity

G = gravitational constant with value 6.67 x 10^{-11} N-m^{2}/kg^{2}

m_{1} = mass of the 1^{st} body

m_{2} = mass of the 2^{nd} body

r = distance between the two bodies

In simple terms,

Gravitational Force = (Gravitational Constant × Mass of first object × Mass of the second object) / (Distance between the centre of two bodies)2.

## Solved examples

**1. Calculate the force due to the gravitation applied to two objects weighing 2 Kg and 5 Kg separated by a distance of 5cm?**

**Solution.** Mass of the body 1 = 2 kg

Mass of the 2nd body = 5 kg

Distance between them = 5 cm

Gravitational constant = 6.67 x 10^{-11} N-m^{2}/kg^{2}

Put all the above values in the Gravitational force formula;

F = Gm_{1}m_{2} / r^{2}

F = 6.67 x 10^{-11} x 2 x 5 / (5 x 10^{-2})^{2}

F = 2.668 x 10^{-7} N

**2. An object weighing 40 Kg gets 200N of energy to the centre of the planet from a distance of 20,000 m. Find the size or mass of the planet.**

**Solution.** Mass of the planet = m_{1}

Mass of the object (m_{2}) = 40 kg

Distance between the both ® = 20,000 m

Force due to Gravity (F) = 200 N

By equation;

F = Gm_{1}m_{2} / r^{2}

200 = 6.67 x 10^{-11} x m_{1} x 40 / (20,000)^{2}

m_{1} = 2.997 x 10^{19} kg

Hence, the Mass of the planet (m_{1}) is 2.997 x 10^{19} kg.