Gravity

Defining Gravity Gravity is the force of attraction between objects that is due to their masses.

Aristotle Ancient Greece around 400 B.C. He believed that the heavier an object is the faster it falls.

Galileo Galileo theorized that all objects will land at the same time when they are dropped from the same height. At an acceleration rate of 9.8 m/s/s.

Gravity Every time you jump, you experience gravity. It pulls you back down to the ground. Without gravity, you'd float off into the atmosphere -- along with all of the other matter on Earth. You see gravity at work any time you drop a book, step on a scale or toss a ball up into the air. It's such a constant presence in our lives, we seldom marvel at the mystery of it -- but even with several well-received theories out there attempting to explain why a book falls to the ground (and at the same rate as a pebble or a couch, at that), they're still just theories. The mystery of gravity's pull is pretty much intact. So what do we know about gravity? We know that it causes any two objects in the universe to be drawn to one another. We know that gravity assisted in forming the universe.

Acceleration Due to Gravity Objects fall to the ground at the same rate because acceleration due to gravity is the same for all objects.

What is Gravity? Galileo helped us understand gravity as a force that exist between the Earth and objects. Newton showed that the same force exist between all objects. Even today, no ones knows why objects attract each other.

It all starts with an apple… Issac Newton 1665 A legend of history has it that while sitting in his garden in Woolsthorpe in 1666, an apple fell on his head, producing his theories of universal gravitation..

Law of Universal Gravitation States that all objects in the universe attract each other through gravitational force. The size of the force depends on: the masses of the objects the distance between objects

What is Weight? A measure of gravitational force exerted on an object. It is the same as force. Weight changes when gravitational force changes. Weight is measured with a spring scale. Weight is expressed in Newton (N). 100 g = 1 N

What is Mass? The amount of matter in an object, and its value does not change. Mass is measured with a triple beam balance. Mass is expressed in kilograms (kg).