Download 10 N

Warm Up - Create a Picture in your IAN for
Each of the Statements Below. Must use AT
LEAST 4 Colors! WILL BE GRADED!
• 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.
• The acceleration of an object as produced by a net force
is directly proportional to the magnitude of the net force,
in the same direction as the net force, and inversely
proportional to the mass of the object.
• For every action, there is an equal and opposite reaction.
Newton’s Laws
of Motion
Regarding Motion,
Newton says:
“In order to move an object with mass,
you need to apply a force”
The greater the mass = The greater inertia => more force is needed
Force
• Force – push or pull and
causes things to accelerate
1000 kg
Balanced vs. Unbalanced
Forces
• Balanced Forces - no acceleration in
any direction
• Unbalanced Forces – one force is
greater than the other causing
acceleration in a direction
Balanced Forces
5N
Object
5N
Equal Pushing
Forces will cancel each other and
produce NO ACCELERATION!
Balanced Forces
If these football players push
on each other equally as hard,
will either one move?
Balanced Forces
Gravity pulls down on you, the ground pushes
back up, KEEPING YOU WHERE YOU ARE!
Unbalanced Forces
10 N
Object
5N
Not Equal Pushing
Forces will not cancel each other out and
produce ACCELERATION!
Net Forces
10 N
Object
5N
What is the net force and in what direction?
(10 N) – (5 N) = 5 N to the right
Net Forces
20 N
Object
5N
What is the net force and in what direction?
(20 N) + (5 N) = 25 N to the right
Net Forces
15 N
Object
30 N
What is the net force and in what direction?
(30 N) – (15 N) = 15 N to the left
Net Forces
10 N
Object
10 N
What is the net force and in what direction?
(10 N) – (10 N) = 0 N
Unbalanced Forces
Forces will not cancel each other out and
produce ACCELERATION!
Balanced vs. Unbalanced
Forces
Video
First Law of Motion
• Inertia – The tendency of an object to
resistance a change in motion; resist a
push/pull (force)
• Newton’s 1st Law of Motion:
– once in motion an object stays in motion - unless acted upon
by another outside force
– An object at rest stays at rest – unless acted upon by another
outside force
Newton’s First Law and You
Because of inertia, objects (including you)
resist changes in their motion. When the car
going 80 m/hour is stopped by the brick wall,
your body keeps moving at 80 m/hour.
Second Law of Motion
• Force = mass  acceleration (F = m  a)
• Acceleration depends on the object’s
mass and the force acting on the object
• More Force = More Acceleration
• More Mass = Less Acceleration
Second Law of Motion
• If you apply
more force to
an object, it
accelerates at
a higher rate
Second Law of Motion
• If the same
force is applied
to an object with
greater mass,
the object
accelerates at a
slower rate
because mass
adds inertia
Second Law of Motion
Second Law of Motion
• A car rolls down a ramp with a force of 2
newtons. The car has a mass of 0.5 kg.
What is the acceleration of the car?
• F=ma
• (2 N)  (0.5 kg) = 4 m/s2
F
m a
Third Law of Motion
• For every action there is an equal and
opposite reaction
Upwards
motion
Downwards
force
Third Law of Motion
Third Law of Motion