Download Forces and Motion

Motion and Forces
What makes us move and why we
move in that particular way…
What Is Motion?
• Motion: when an object changes
position over time when compared
with a reference point
Object
In
Motion
Reference
Point
How Can We Describe
Motion?
• 3 Ways To Categorize Motion
1. Position
2. Direction of Motion
3. Speed
Which way did he go,
which way did he go???
Follow The Directions!!!!
The direction of the
objects motion is
dependent on the
reference point
If the reference point
changes, the direction
of the object can also
be looked at differently
What Makes An Object Move?
• Force: a push or pull on an object
Characteristics of Forces
1. Have size
2. Direction
3. Units = Newtons
40.0 Newtons
Forces Control The Motion of
an Object
• If an object is in moving or even if it is sitting
still, there are still forces acting upon it
If the forces acting on the
object are balanced, or
equal to one another but
in opposite
directions…then the
object doesn’t move.
If one of the forces is
larger, it will move the
object in the direction of
that force
All Forces Control The Motion
of the Object
• We can use something called a Force
Diagram
Net Force
• Easy Calculation
2 Scenarios
1. If the forces are moving in the
same direction, add them
together
2. If the forces are moving in the
opposite direction, subtract
them, leaving the object to move
in the direction of the greater
force
Example
Newton’s Laws
1. An object in motion tends to stay in
motion unless acted upon by an
outside force
2. Force = mass x acceleration
3. For every action, there is an equal
and opposite reaction
One Force Calculation
Example
5.0 m/s2
Force = mass x acceleration
Force = 500.0 kg x 5.0 m/s2
Force = 2500.0 N to the left