Download Newton`s Laws of Motion Notes

Newton’s Laws Notes
Term
Definition or Information
Sir Isaac
Newton
He figured out three basic laws that explain
common forces and how they interact to
produce motion.
First Law
(Law of
Inertia)
an object will remain at rest or move with a
constant speed unless a force is applied
Second Law
(Law of
Momentum)
an object acted upon by a force will
accelerate in the direction of the force
a. The larger the net force, the
greater the acceleration.
b. An object’s mass and acceleration
are inversely related: the greater
the mass, the lower the
acceleration.
Third Law
---for every action there is an equal and
opposite reaction
a. The forces on the wall and the ice
skater are equal in size and opposite
in direction. Although there are two
objects involved, each object exerts
one force and experiences one
force. The wall does not move
because it has a lot of inertia.
b. When the fuel burns, the engine
exerts a downward force on the
exhaust gases. The gases exert an
equal and opposite upward force on
the rocket.
c. When a swimmer pushes against
the water (action), the water pushes
against the swimmer (reaction). The
reaction force pushes the swimmer
forward.
Examples/Diagrams
Force = mass x acceleration
or
F = ma
force
push or pull; usually more than one force is
acting on an object
net force
sum of all the forces acting on the object
balanced forces forces that are equal in size and opposite in
direction
unbalanced
forces
two or more forces acting on an object that
do not cancel, and cause the object to
accelerate
friction
inertia
force that opposes motion between two
surfaces that are touching each other
1. natural tendency of an object to
resist any changes in motion
(depends on mass)
2. The greater the mass of an object,
the more inertia it has. When inertia
becomes greater, it becomes more
difficult to slow down, speed up, or
change the direction of a moving
object. It is also harder to make an
object with greater inertia start
moving if it is at rest.
velocity
the rate of motion (speed/direction)
terminal
velocity
It is reached when the force of gravity is
balanced by air resistance. Air resistance
depends on size and shape of the object.
Air resistance is the force air exerts on a
moving object. This force acts in the
opposite direction to that of the object’s
motion. In the case of a falling object, air
resistance pushes up as gravity pulls down.
speed
rate of motion or rate of change in position
S=d/t
or Speed = distance/time
distance
how much ground is covered by an object,
regardless of its starting or ending position
The Indian Nation event was a 5-k race. The
participants ran 5 kilometers.
displacement
--- an object's change in position
considering its starting position and final
position
---direction in straight line (not time)
**travel time to the store is different than
the actual distance to the store in a straight
line (GPS)
---runner runs 400m around the track and
back to the starting point—the displacement
is zero
---people were displaced after Katrina
---water displacement
distance= speed X time (d = vt)
acceleration
rate of change in velocity
weight
(gravitational
force)
measure of the force of gravity on an object,
usually the force between Earth and an
object at its surface
momentum
--a property a moving object has due to its
mass and velocity
--momentum of an object doesn’t change
unless its mass, or velocity, or both, change
--Momentum can be transferred from one
object to another.
momentum=mass x velocity
( p=m  v )