What is Gravity? | Definition, Types, Formula & Examples

by

What is Gravity?

Gravity is the mysterious force that brings everything down to Earth. But what is it? Turns out everything has gravity. It’s just that some objects, like the Earth and the Sun, have a much greater gravitational pull than others.

The gravity of an object depends on its size. Exactly how much mass it has. It also depends on your distance from the subject. The closer you are, the stronger the force of gravity.

Why is Gravity Important to us?

Gravity is very important in our daily lives. Without Earth’s gravity, we would fly in an instant. We should all be attached. If you hit a balloon, it will fly away forever. While it might be fun to try for a few minutes, we certainly can’t live without gravity.
Gravity also matters on a larger scale. It is the Sun’s gravity that keeps the Earth in orbit around the Sun. Life on Earth needs light and heat from the Sun to survive. Gravity helps the Earth keep the right distance from the Sun, so it doesn’t get too hot or too cold.

Who discovered Gravity?

The first person to drop a heavy object on their toe knew something was up, but gravity was first described mathematically by scientist Isaac Newton. His theory is known as Newton’s Law of Gravity. Later, Albert Einstein would make some improvements to this theory in his theory of relativity.

What is Weight?

Weight is the force of gravity on an object. Our weight on Earth is the force Earth’s gravity exerts on us and the force it pulls us to the surface.

Do objects fall at the same speed?

Yes, this is called the principle of equivalence. Objects with different masses will fall to Earth at the same speed. If you bring two balls of different masses to the top of a building and drop them on the ground, they will hit the ground at the same time. In fact, there is a specific acceleration at which all objects fall, called standard gravity, or “g”. This equates to 9,807 meters per second squared (m/s2).

Interesting Facts about Gravity

Ocean tides are caused by the moon’s gravity.

Mars is smaller and less massive than Earth. As a result, it has less gravity. If you weighed 100 pounds on Earth, you would weigh 38 pounds on Mars.

The standard gravity of the Earth is a force of 1 g. When riding a roller coaster, sometimes you can feel more g-forces.

Maybe up to 4 or 5 g. Fighter pilots or astronauts can sense more than that.

At some point during the fall, the frictional force of the air will equal gravity and the object will have a constant velocity. This is called terminal velocity. For a skydiver, this speed is about 200 km/h!