1 st Law of Motion Vocabulary Terms

Sir Isaac Newton ➔ Mathematician ➔ Physicist ➔ Observed the apple falling from the tree = created the theory of gravity ➔ His book, Principia outlined the laws of motion

But wait… what is motion?

Motion - An object is in motion when it changes its position over a period of time relative to a specific reference point.

Reference Point - A point used to define the location of another point.

1st Law of Motion - An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. ➔ Often called the “Law of Inertia” ➔ Means = There is a natural tendency for objects to keep doing what they are doing.

Force - A push or pull. There are two main types of forces: ➔ Unbalanced forces produce a change in motion. ➔ Balanced forces will NOT cause a change in motion.

Unbalanced Force Balanced Force

Forces cont.. Net Force is the combination of all of the forces acting on an object.

Inertia - The tendency of an object to resist change in motion. ➔ Mass (the amount of matter in an object) is a measure of inertia. ➔ The greater the mass, the greater the inertia.

But what about Friction?

Friction - A force that slows the motion of an object. ➔ Can cause a moving object to slow down and stop. ➔ Occurs because the surface of any object is rough.

Question to Think About: Would changing the mass of the object change the results?