Newton's three laws of motion are: 1) An object at rest stays at rest and an object in motion stays in motion with constant velocity unless acted upon by an unbalanced force. 2) The acceleration of an object depends on the net force acting on it and its mass, expressed by F=ma. 3) For every action there is an equal and opposite reaction.

1. Newton’s First Law
An object at rest remains at rest.
An object in motion remains in motion at a constant
speed and in a straight line (constant velocity) unless
acted upon by an UNBALANCED force.

2. Newton’s Second Law
The acceleration of an object depends on the mass
of the object and the force applied.
It is expressed mathematically with the equation
F = ma

3. Newton’s Third Law
If an object A exerts a force on object B, then object B
must exert a force of equal magnitude and opposite
direction back on object A.
*Forces always occur in pairs. One object cannot exert a force
on another without experiencing a force itself. We sometimes
refer to this law loosely as action-reaction, where the force
exerted is the action and the force experienced as a
consequence is the reaction.

4. Net force = ZERO Newtons
Does NOT cause acceleration
No change in motion

5. Net force ≠ ZERO Newtons
Causes acceleration
Change the motion of an object

6. A push or pull

7. A measure of the
amount of matter in
an object.

8. A measure of the
rate of change in
position over time

9. The tendency of an
object to resist a
change in motion

10. The force exerted
on object A by
object B.

11. The equal and opposite
force exerted on object
B by object A.

12. A change in velocity:
Speeding up
Slowing down
Turning

14. A car accelerates because the ground
pushes forward on the wheels in
reaction to the wheels pushing
backward on the ground. You can see
evidence of the wheels pushing
backward when tires spin on a gravel
road and throw rocks backward.

15. When more force is applied to the same
mass, that mass will experience greater
acceleration.

16. Bigger, more massive vehicles
require more force to acceleration
than smaller, less massive vehicles.
This is why smaller cars are
generally more fuel-efficient than
large trucks and SUVs.

17. If one drove a car directly into a brick wall, the car
would stop because of the force exerted upon it by
the wall. However, the driver requires a force to stop
his body from moving, such as a seatbelt, otherwise
inertia will cause his body to continue moving at the
original speed until his body is acted upon by some
force (such as the windshield… ouch!).

18. When playing football, a player is
tackled and his head hits the
ground. The impact stops his skull,
but his brain continues to move
and hit the inside of his skull. His
brain is showing inertia.