# How to calculate g

Gravitational acceleration, commonly denoted as “g,” is the acceleration experienced by objects due to the force of gravity acting upon them. This fundamental concept plays a vital role in various fields of physics, particularly when studying the motion of objects near Earth’s surface. In this article, we will explore different ways to calculate gravitational acceleration and how it impacts our daily lives.

**Newton’s Law of Universal Gravitation**

The first step toward understanding how to calculate g is knowing the underlying principle that governs gravitational force. Sir Isaac Newton formulated the Law of Universal Gravitation, stating that every point mass attracts every other point mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between them. Mathematically, this can be expressed as:

F = G * (M1 * M2) / R^2

Where:

– F is the gravitational force between two masses

– G is the gravitational constant (approximately 6.674 × 10^-11 N(m/kg)^2)

– M1 and M2 are the masses of two objects in kilograms

– R is the distance between their centers in meters

**Calculating g for Objects Near Earth’s Surface**

When dealing with objects near Earth’s surface, we can simplify Newton’s Law of Universal Gravitation formula for determining g:

g = G * (Me / Re^2)

Where:

– g represents gravitational acceleration (measured in meters per second squared, m/s^2)

– Me is Earth’s mass (approximately 5.972 × 10^24 kg)

– Re is Earth’s average radius (approximately 6,371,000 meters or 6,371 km)

After plugging these values into the formula and solving for g, you’ll get a value of approximately 9.81 m/s^2. This number represents the average gravitational acceleration on Earth’s surface, which varies slightly depending on your location.

**Using g to Calculate the Gravitational Force on an Object**

Now that we have the value of g, we can use it to find out the gravitational force acting upon an object near Earth’s surface with the help of the following formula:

Fg = m * g

Where:

– Fg is the gravitational force acting on an object (in Newtons)

– m is the mass of the object in kilograms

– g is the gravitational acceleration (9.81 m/s^2)

**Conclusion**

Knowing how to calculate gravitational acceleration (g) is essential for solving problems related to motion, weight, and freely falling objects on or near Earth’s surface. It helps us understand everyday phenomena such as why objects fall when dropped and how our weight changes slightly at different altitudes and latitudes.