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.