Download Weightless water trick W

FORCES Activity Sheet 1
Activity
Acti
iv
viity 1
Mark the force
orce of gravity on this picture of Oblivion.
What is a force?
A force is a push or a pull. Forces can change the speed,
direction and shape of an object. Arrows are used to show
the direction of a force. Sometimes a force can be applied
without any contact. Gravitational force (gravity) pulls
everything down towards the earth.
Balanced forces
If something is not
accelerating, there must
be two forces balancing
one another out.
Measuring
Meas
su
forces
The ssize of gravitational attraction
ractttion
ion is
called weight. This is measured
red in
newtons (N). On earth, a masss of 1
newto
kilogram
kilogra
am weighs 10N, so a chair
weighing
weigh
hing 5kg is pulled towards
rds earth
50N.
with a force
for of 5kg x 10N/kg = 50N
N.
Activity
Acti
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viity 2
Unbalanced forces
If forces are unbalanced an object will begin to move, speed
up or slow down. When Oblivion leaves the plunge tower
there is no longer an upward force to balance the downward
pull of gravity so riders accelerate towards the ground.
Weightless water trick
W
Drill or punch two holes in a plastic or paper cup
(approximately half a centimetre in diameter) on
opposite sides of the cup.
Fill the cup to the rim with water. The water will flow
from the cup through the holes.
Now refill the cup, cover the holes with your fingers,
and drop the cup from an elevated position. The
water won’t flow out of the holes during this free fall.
Why do you think this happens?
Be careful - although the water won’t
spill during the fall, it will spill when it
hits the ground.
FORCES Activity Sheet 2
Friction
F
Frict
i
Friction is present when:
• two surfaces are gripping
• two surfaces are sliding over one another.
Friction can slow down or stop a moving object. When the brakes are
applied to a theme park ride, the force of friction brings the ride to a stop.
Air resistance
When an object moves through air it experiences two forces; friction
on and
air resistance. For a ride such as Air to speed up, the driving force needs
to be bigger than the resistive force. If the resistive force is bigger, the
he ride
will slow down. In both instances the forces are unbalanced.
Reducing friction by streamlining and lubrication
As a rollercoaster travels down its track it gains speed. There are large frictional forces between the rollercoaster wheels
and the track and air resistance between the rollercoaster and the air.
• To reduce friction, the rollercoaster’s wheels are coated in lubricant.
• To reduce air resistance, the rollercoaster is streamlined to cut through the air.
Water and resistive force
Moving throu
through water causes a resistive force. Water slows riders down as they reach the bottom of thee final drop on
The Flume.
FORCES Activity Sheet 3
Activity
Acti
A
tiiiv
viity 1
Make a model of The Flume
M
Set up your model as shown in the diagram below.
Add a small amount of water to the tray so that it just covers the track. Measure the depth of the water.
Launch a ball or a toy car from a set point on the model track and measure the distance it takes to stop.
Change the depth of the water and repeat the exercise. Record your findings in a table.
Analyse your findings to assess whether the depth of water affects the distance travelled.
Change the point from which you launch the ball/
toy car and repeat the experiment.
Depth of water
Distance to stop
Wooden
Blocks
Track
Water
Shallow Trough
or Dish
FORCES Activity Sheet 4
Activity
Acti
iv
viity 1
Writ
Write down all the wo
words you can think of on the subject of forces.
Can you link two or more of these words together?
Activity
Acti
iv
viity 2
Your teach
s of cards. Some of the cards are
teacherr will give you a set
key word cards
c rds and some of the
th cards are description cards. You
must match the key words to their description.
Activity
Acti
iv
viity 3
Have a go at making your own cards.
When the
th Skyride is moving,
movin two horizontal forces affect its motion. One is air
resistance and the other is forward force.
Explain how the molecules in the air cause air resistance.
________________________________________________________________
air
air
resistance
resistance
foward
foward
force
force
Explain why air resistance is larger when Skyride is travelling faster.
________________________________________________________________
Compare the sizes of the forward force and air resistance when Skyride is speeding up.
______________________________________________________________________________________________
Compare the size of the two forces while Skyride is moving at a steady speed.
______________________________________________________________________________________________
The forward force would have to be larger if Skyride was travelling at a steady pace of 30mph rather than 15mph.
Why is this?
______________________________________________________________________________________________
__