Download Force - SewardScience8

Force: push or pull
 all forces have size and direction
 measured in Newtons (N)
An object will
speed up,
slow down,
or turn
Only if something is
pushing or pulling on it.
Usually, more than one force
is acting on an object.

Net Force: Combination of all forces on an
object
 Determines motion of object
(similar to total velocity)
20 N
25 N
Net Force
25 N + 20 N = 45 N to the right
When forces act in the same direction, you add the forces
to determine the net force. The net force will be in the
same direction as the individual forces.
When two forces act in
opposite directions,subtract
the smaller force from the
larger force.
The net force will be in the
same direction as the larger
force.
35 N
20 N
Net Force
35 N – 20 N
= 15 N Up
This is
ZERO
fun!!!
12 N
12 N
Eat it!!!
Don’t
wipe
that
on
me!
12 N
20 N
What force was missing in the video?
Friction: slows motion, can cause moving objects to
slow down and stop
Force
Between
Surfaces
As force increases, friction
increases.
Source
of
Friction
Surface
Roughness
The rougher the surface is, the
greater the friction is.
Kinetic Friction: “moving”, friction between
moving surfaces
Rolling and Sliding Friction
Unbalanced Force—Net Force Doesn’t = Zero
Static Friction: “not moving”
Balanced Force—Net Force = ZERO