Draw arrows to show the forces
acting on the parachutist.
Balanced and unbalanced
forces
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parachutist
accelerating
in free fall
1
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2
Match the boxes.
parachutist at a
constant speed
in free fall
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3
How do we show forces?
weight
Force created when an
object has to move through
air.
air resistance
A force when an object is
moved either forwards or
backwards.
upthrust
A force created by gravity
attracting an object.
friction
Force created when 2
objects rub together.
push / pull
A force that pushes an
object up when it is in a
liquid.
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Balanced and un-balanced forces
What is happening?
constant speed
accelerating
stationary
• Which way does the engine move the car?
• Are there any forces trying to stop the car?
• What direction are they in?
• How big are they?
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accelerating
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constant speed
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or stationary
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1
Balanced or unbalanced?
Draw arrows on the pictures to match the motion.
Are the forces on
the rocket
balanced?
No
speeding up
constant speed
Yes
slowing down
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What do unbalanced forces do?
Which way is the overall force?
What is happening to the objects in the examples below?
Who will win the tug of war?
speeding
up
floating
slowing
down
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A
sinking
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B
What is the resultant force?
50 N 
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Summary
If the forces on an object are the same size and in the
balanced.
opposite direction the forces are ...................
If this happens the object’s motion does not change. If
the car is moving it must be travelling at a
...............................
constant speed.
If the forces are not the same size they are
unbalanced. These can change the motion of an
........................
object, causing it to
accelerate
...................... or decelerate.
....................
(speed up)
(slow down)
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2