I've heard of Isaac Newton.

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• Isn't that a type of cookie?

Law #1:  

An object at rest tends to remain at rest.

Law #1:  (continues)

An object in motion tends to stay in motion...

Law #1:  (continues)

at a constant velocity and in a straight line...

Law #1:  (concluded)

until it is acted upon by an unbalanced force.  

Newton's 1st Law

(Law of Inertia)

An object at rest tends to remain at rest. An object in motion tends to remain in motion at a constant velocity and in a straight line until it is acted upon by an unbalanced force.  

Newton's 2nd Law

F=ma

Force equals mass times acceleration.

F = ma

SI (International System of Units)

F=ma

SI units for Force:

Newtons

SI units for mass:

kilograms

SI units for acceleration:

m/s²

REAL LIFE

• Elon Musk

• rockets

• cars

F=ma

F = ?

m = 5,000,000 kg

a = 70 m/s²

^{First, drop all units and fill in the known variables.}

^{Second, know that numbers and letters next to each other imply multiplication.}

^{Then, multiply the numbers (ma) and this equals the Force.}

^{Last, Force is measured in Newtons.}

Show your work:

F=ma

F = ?

m = 5,000,000 kg

a = 70 m/s²

F = 5,000,000 x 70

F = 350,000,000 Newtons

Newton's 3rd Law

Action/Reaction

The action force is equal in magnitude to the reaction force and opposite in direction.

​

Example

paddle moving back =

boat moving forward

Example:

Rocket fuel = action force

Rocket propelling = reaction force