Movement, energy and balloon
ROCKETS
Why d
the bal oes
loo
move? n
LUBRICANTS REDUCE FRICTION
Friction can be useful (for example in the brakes of a car and gripping your shoes to the floor) or it can be
a problem (trying to get a rocket into space or back to Earth, or when you want a sports car to break the
speed record). Friction brings the balloon to a rocket balloon to a stop. To reduce friction, use a lubricant.
OBJECTIVES
To understand the effect of friction on the
movement of objects.
To communicate ideas to a group.
STARTER
Label one side of the room “true” and the
other “false”. Read out the statements on
page 2 and ask children to move to either the
true side or the false side of the room or play
“Taboo” (see page 2). At the end of the game,
ask children to sit in a circle
STIMULUS
If possible, set the following up in
advance of the lesson. Set two chairs
approximately 4 metres apart. Thread a straw
through a length of string. Tie the ends to
each chair so that the string is more than 30
cm above the ground. Inflate (but do not tie)
a rocket balloon. Fold the neck over and
secure with a clothes peg to prevent the air
coming out. Pull the straw to one end and
tape lengthways along the balloon.
Ask children to be prepared to observe
what happens and to describe what they see
to a partner. Remove the peg and watch the
rocket travel along the string. Repeat the
Resource for Teachers
experiment, this time rub some washing up
liquid solution or oil along the string.
ENQUIRY
GENERATING QUESTIONS
dialogue, without putting their hands up.
After allowing the children some thinking
time give each pupil an index card and ask
them to record a question which they would
like to discuss. Arrange the class into groups
of 3 and ask them to work together to decide,
with reasons, on one out of the 3 questions
put forward. However they must
communicate silently within their group. They
may write, use body language or any other
silent method, but they must not talk. Once
the groups have decided on a question, the
teacher then records them on a flip chart.
Allow children to take part in open
REFLECTING ON THE ENQUIRY
Place 3 A3 sheets of paper on the floor,
labelled knowledge, understanding and
skill. Then give each student 3 different
coloured post-it notes and ask them to reflect
in silence about what new knowledge they
have, which skills they have used and
something they still do not understand. Ask
the children to then record the information on
the post-it notes and stick to the
corresponding piece of card.
SELECTING A QUESTION
Read all the questions once, asking each
group their reason for submitting their
question. Take a secret vote. Do this by
asking the children to close their eyes, then
reading out one question at a time. If the
pupil wants to vote, they place their palm
upwards on their knee. Count and record the
number of votes for each question on the flip
chart. The question with the most votes will
be the focus of the enquiry.
1
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E
Wood slides
over carpet easily.
T
R
U
F
A sleigh
travels faster over
snow than grass.
Rubbing your
hands together
creates heat.
T
T
It is easy to lift
jelly with
chopsticks.
Friction is not
useful
Friction slows
things down.
T
T
F
Resource for Teachers
FA
You can
increase friction
by putting oil
between rubbing
surfaces.
L
Friction is
needed to make
cars move.
E
F
s
F
2
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Friction
Taboo
Divide the class into groups of 4 and print one set of the Taboo cards for each group. Divide the cards evenly between each person within the
group. The first player must describe the word in bold to the other members of their group without using the other words on the card. The first
person to get the correct word wins that card, the overall winner will be the pupil with the most cards at the end.
SLIDE
RUB
PUSH
Swing
Park
Hands
Mistake
Pull
Swing
BALLOON
STRING
ROCKET
Party
Hot Air
Tie
Rope
Moon
Space
STRAW
STRING
ROCKET
Drink
Bed
Tie
Rope
Moon
Space
AIR
FRICTION
FORCE
Oxygen
Breathe
Rubbing
Sliding
Push
Pull
Resource for Teachers
3
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forces
and
motion
BALLOON
ROCKETS
FORCES
• When a balloon is blown up it is filled with gas. The gas particles hit
against the inside of the balloon. The particles hitting the inside if the
balloon are what creates the pressure.
• When the balloon is released the compressed air inside the ballon rushes
out into space and the reaction is to thrust the balloon forward like a
rocket. The balloon moves in the opposite direction to the escaping gas.
• The balloon and straw move along the string until the balloon is
completely deflated.
• Newton’s third law of motion states that: “for every force (or action) there
is an equal and opposite force”, in other words if you push against a wall,
it will push back against you as hard as you are pushing it. For example;
when the gas escapes, the force of it escaping is balanced by a reaction
force of the balloon moving in the opposite direction to the gas.
• Friction is the force between two surfaces when they rub together, it is a
force that resists motion. There is friction between the straw and string.
• When two smooth surfaces rub together there is little friction.
• When two rough surfaces rub together there is more friction.
• Friction reduces when there is a liquid between the two surfaces e.g.
washing up liquid.
To do this demonstration
you will need 2 chairs,
string, a peg, a balloon
rocket, sellotape, a straw
and some oil or washing
up liquid solution.
• Sounds are made by vibrations, for example the strings on a violin or a
guitar vibrate to produce the sound, placing a blade of grass between
your thumbs and blowing it, even your own voice is a result of your vocal
cords vibrating. The balloon will make a noise as it deflates because as
the air escapes from the balloon it causes the rubber that the balloon is
made of to vibrate.
Oil i
lubri s a
redu cant. It
ces f
r
betw iction
een
surfa
ces.
Resource for Teachers
4
The rocket balloon makes
a loud sound as the air
escapes. Sound is made
by vibrations. The rubber
neck of the rocket balloon
vibrates as the air
escapes.
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