1. Physics
Mr. Dunn
Science

2. Physics Defined
The natural science that involves the study of matter and its motion through space and time, along with related concepts such as energy and force.
In other words…the study of all forces and their impacts on the environment.

3. Aristotle (Greek)
Aristotle was the first to try and explain the natural world.
He based all of his ideas on logic, observation, and thought.
This allowed him to get the right answer to questions, but also led him to wrong conclusions without testing.
Aristotle made many great observations that Galileo and Newton used to arrive to their conclusions.
Heavy things fall and light things rise.
Objects always want to be at rest.
Lacked technology to prove ideas.

4. Galileo Galilei (Italian)
He rolled and dropped objects to discover the true aspects of motion.
Discovered that bodies do not fall with velocities proportional to their weights.
He later found out that the velocity is proportional to time and independent of both weight and density.
He was able to prove his work, unlike Aristotle.
A force is not necessary to keep something in motion.
Idea of inertia.

5. Isaac Newton (English)
Developed laws for motion and gravity that explain why objects move.
Came up with the theory of gravity.

6. Newton’s First Law
An object in motion will stay in motion, and an object at rest will stay at rest unless an unbalanced force acts on it.
Also known as the Law of Inertia.
Inertia is an object resisting changes in their state of motion or rest.
In other words, an object in rest wants to stay at rest, and an object in motion wants to stay in motion.
Force is required to overcome an object’s inertia.
A force is a push or pull that can cause the motion of an object to change.

7. Examples
Car stopping
Water in a baking pan

8. Motion
The change in the position of an object over time.

9. Balanced and Unbalanced Forces
When adding up all of the forces that are acting on an object, you get the net force.
If the net force = 0, the forces are called balanced.
The object is either at rest, or moving at a constant speed in a straight line (velocity).
Speed is an object’s rate of motion.
If the net force ≠ 0, the forces are called unbalanced.
The object is accelerating.
Acceleration is a change in speed or direction.