Newton's first law states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. Newton's second law states that acceleration depends on the net force acting on an object and its mass. Newton's third law states that for every action there is an equal and opposite reaction. Momentum is the product of an object's mass and velocity, and the law of conservation of momentum states that the total momentum of a system remains constant unless an outside force acts on it.

1. Newton’s Laws

2. Newton’s 1st Law (1)
• Newton’s first law states that an
object will remain at rest or
moving at a constant velocity
until acted upon by an
unbalanced force.

3. Newton’s 1st Law (2)
• What does that mean?
• Basically, an object will keep doing
what it’s doing until something
changes it.
• Examples?

4. Newton’s 1st Law (3)
• Newton’s 1st law is also referred to
as “The Law of Inertia”
• Inertia: is the tendency of an object
to resist a change in it’s motion.
– Example: Remember the car crash
video? If not wearing a seatbelt, the
passenger’s inertia keeps them moving
forward as the car stops (cracking head
on windshield).

5. Newton’s 2nd Law (1)
• Newton’s second law of motion states that
acceleration depends on the net force
acting on the object and on the
object’s mass.
Acceleration = Net Force/Mass
**this is acceleration due to force; different
than acceleration due to velocity and time

6. Newton’s 3rd Law (1)
• Newton’s 3rd law states that if one
object exerts a force on another
object, then the second object
exerts a force of equal strength
in the opposite direction on the
first object.

7. Newton’s 3rd Law (2)
• In other words: For every action,
there is an equal an opposite
reaction.
• Examples?

8. Momentum (1)
• Momentum: a characteristic of a
moving object that depends on both
the mass and velocity of the object.
Momentum=Mass x Velocity

9. Momentum (2)
• The LAW of conservation of
momentum states the total
momentum of any group of objects
remains the same, or is conserved,
unless outside forces act on the
objects.
– Friction is one of the outside forces that
can act on the objects and take away
momentum.

10. Momentum (3)
• What does that mean?
• Well… Momentum can be transferred
from one object to another, but it is
never lost.
– Example? Playing pool!!!

11. Momentum (4)
• For a great visual….. Page 398 in the
text book.
• This will show us the difference in
how momentum works with two
moving objects, one moving object
and two connected objects.