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TRANSCRIPT
Forces and Motion
Essential Standard 1.2
Understand the relationship between
forces and motion.
Learning Objective 1.2.2
Classify frictional forces into one of four
types: static, sliding, rolling, and fluid.
I Can StatementsAt the end of this lesson, you should be
able to say, with confidence:
• I can explain the relationship between force
and motion
• I can distinguish between balanced and
unbalanced forces
• I can describe four types of frictional forces
A Force is a Push or Pull that One Object
Exerts on Another
Force
In order for there to be any motion, a force must
be applied.
The direction of the
motion will be in the
direction of the force
applied.
Force and Motion
In order to change the direction of the motion,
another force has to be applied.
Changing Motion
When two or more forces combine at the
same time, they create a net force.
Net Forces
Force Force Net Force
Balanced forces occur when the forces are
equal in size and opposite in direction
Balanced Forces
Force 1 Force 1 Force 1 Force 1
Net Force 2 Net Force 2
Force 1 Force 1 Force 1 Force 1
Net Force 2 Net Force 2
No MovementBecause balanced forces are equal in size and
opposite in direct, they cancel each other out, so
the net force is zero and no movement occurs.
Net Force = 2 – 2 = 0
Unbalanced forces are unequal in size and the
direction of the movement is determined by the
larger force.
Unbalanced Forces
Net Force 3 Net Force 2
Total Net Force = 3 - 2 = 1
Friction is the force that opposes motion between two surfaces that are touching
each other.
Friction
Even though friction opposes motion, without it we wouldn’t be able to walk or drive.
Friction
Static FrictionStatic Friction occurs between two objects that
are not moving.
In order to move an
object, you have to
apply enough force to
overcome the static
frictional force.
Static Friction is the hardest frictional force to
overcome.
Sliding Friction is the force that opposes the
motion of two surfaces sliding past each other.
Sliding friction is
easier to overcome
than static friction.
Sliding Friction
Isn’t it much easier to slide a heavy box than
carry it?
Rolling friction occurs between an object that is
rolling and the surface it is rolling upon.
Rolling Friction
Rolling friction is easiest frictional
force to overcome.
Fluid FrictionFluid friction occurs when a solid object moves
through a fluid.
Fluids are anything that flows, so both water
and air are fluids. (Air Resistance)
StreamliningStreamlined objects try to reduce fluid friction by
helping the fluid flow over the object.
ParachutesParachutes are designed to increase air
resistance to slow down movement by increasing
surface area.
The End