parachute

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parachute
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Materials used
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Materials used

• Appearance of parachute
• 1. nylon thread X8
• 2. white plastic bag X1
• 3. Straw X12
• Decoration
• 1. newspaper 3. magazine
• 2. cellophane

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Design
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Design
gtgtThe material used does not need to be
purchased. gtgtThe material, such as plastic
tablecloth, spongeetc ,may be reused
again. .We use lighter material to decorate the
parachute. gtgt Cellophane, magazine picture (x1),
gtgtTo reduce the mass of the whole parachute.
To increase the air resistance so as gtgtgtto
protect the egg
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application of physics principles
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application of physics principles
1.Terminal velocity
(1) At the very beginning, F lt W ? net force
gt 0 ? the parachute accelerates ( velocity v
?) (2) v? F ? (3)Finally, W F ? net force
0

?the
parachute move with constant speed( terminal
velocity)
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application of physics principles 2
2. Time of impact

The bottom of the parachute is stuck with a
piece of sponge. When the parachute reaches the
round, the compression of the sponge increases.

This can reduce the
impact force acting on the parachute
Thus the parachute and egg wont be damaged so
easily.
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results of experiment
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results of experiment
We tried twice to have the parachute fallen from
the 4/F to the ground. Firstly, it was not
successful. Secondly, it took about 12 seconds to
reach the ground and the egg didnt break after
falling from the 4/F.
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conclusion and discussion
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Conclusion

• We learn a lot from this assignment. Not only can
  we learn the principle of Physics(Force and
  Motion), we can also learn the importance of
  cooperation in team work.
• We have a lot of fun on that and hope that the
  same type of assignment can be organized next
  time for us to apply our skills and knowledge.

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Learning(Force and Motion)

• .how air resistance affects the motion of the
  parachute
• .the fluid friction can oppose the motion
• .increase the size of the parachute can greatly
  increase the air resistance and when air
  resistance is the same as the weight of the
  object , the terminal speed of it can be reached.
  Reducing terminal speed make it safe enough for
  the egg to land onto the ground.

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Learning(cooperation)

• .We need to have a close cooperation between each
  member so each person can do her own job
  properly.
• . We can do the job properly,our friendship can
  be strengthened during our meeting.

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Discussion

• Although we can apply the knowledge of Physics to
  protect the egg, we have thought about some
  improvement for this assignment so that we can
  improve our skills on it.

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• Method 1
• Make the size of the parachute bigger.
• Reason to increase air resistance and reduce the
  terminal speed.
• Method 2
• Reduce the mass of the object which contains the
  egg
• Reasonthe difference between the weight and air
  resistance is smaller and rate of increase of
  speed (acceleration) will be smaller.

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comments of group members
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comments of group members
Ko Wing Ki 4E (4)
When I know that Physics assignment is to make a
parachute to protect an egg ,I am interested in
it . Although we have learned much knowledge on
each subject, those are the basic for us to know
about or learn, we have no chance to apply the
knowledge and the theory such as the Newtons
first law of motion to our daily life except the
experiments during the lesson. It is more
important for us to apply the knowledge.
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Since each person in my group cooperate properly,
we finished it in a few days only. I think that
the most difficult things are the design of the
container which contains the egg and how to apply
the knowledge of the laws of force and motion so
we need to search the Internet for a long time.
Unfortunately, I cannot find something useful.
Finally, I use my own idea on the design. I try
to use some reusable materials such as newspaper
and magazine paper to cover the container so it
can reduce the weight of the object and not too
much money is spent on the project. According to
the Newton law of motion, since the surface area
is increased when the parachute opens , the air
resistance is greatly increased and so the
terminal speed can also be reduced.
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Luckily, the time of the parachute to reach the
ground is the greatest. I felt very surprised. I
have learned many things in the assignment - the
principle applied and the importance of
cooperation. Based on my knowledge of Economics,
the division of the labour will increase the
productivity of the production since each person
concentrates on different job. Also, I can review
on my past experience when I was in primary
school. I have done the same assignment , how to
use the parachute to protect the egg and I know
that one of the important thing is to use
suitable numbers of rope. I hope that I can have
another chance to do the same type of assignment
and improve my skills.
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Kong Ki Chi 4E (5)
This is the first time we made a parachute. We
tried our best to do this project, although we
didnt know if it is success or not. We tried to
cut a hexagon, circle and square and we thought
square parachute was the best. We tried a small
one but it was falling too fast and was not
stable. Then we tried a bigger one, it was better
than the small one. Also, we used a long rope
instead of a short one. The egg didnt break
after falling from the 4/F .I think the parachute
design is more important than the protection of
the egg.
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Lam Nga Ching 4E(8)

• After this activity , I know that cooperation is
  very important. We need to have a close
  cooperation between each person so each person
  can do their own job properly. We have done a lot
  of experiments and have discussion after each
  trial.
• At last, our parachute spends the longest time to
  land compared with other groups in our class. I
  am very proud of my group and myself.

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Making our parachute, we consider how air
resistance affects the motion of the parachute
and how to reduce the impact force acting on the
parachute on landing .This help us to revise the
Newtons Law of motion.We also search information
of parachute through the Internet. We learn much
extra knowledge about parachute. I also find
physics very important in our daily life. Physics
can help improve our living standard .
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When my classmates tested their own parachutes,
the ambiance was very exciting. I was completely
immersed in this activity. I was also very
excited. When our teacher announced which group
had the longest time of fall, all of my
classmates were very nervous . Members of my
group were very happy as our parachute spent the
longest time to fall. I also found many
beautiful and creative parachutes being made by
my classmates. I think this activity is
meaningful and exciting.
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Lam Yuen Man 4E(9)
I think this activity is very meaningful. To make
a parachute, we have to revise the related topics
such as terminal speed. Also, we have to find
information on nternet or books. Although it is
quite hard to find useful information from the
bulk of things on the internet, it is a chance
for me to be active in learning. Doing research
on the parachute, I understand more on parachute
and the physics principles behind. Therefore, the
activity allows us to do revision on the things
that we have learnt and leads us to be active in
learning.
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• Besides, making a parachute allows us to apply
  physics in our daily life. This not only let us
  have a better understanding of the topics that we
  have learnt, but also motivates me to learn.
  After doing this project, I understand that
  physics are everywhere so I should try to be more
  curious to find out physics in daily life.

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In addition, when we made the parachute, our
group members were working together. We have
failed at the first time, but after having
discussion on improving the parachute and several
trials to test the function of the parachute, we
succeeded. That gives me a great feeling that it
is worth paying effort to make the parachute and
also gives me a sense of satisfaction of team
work. Also, when we dropped the parachute from
the 4th floor in the New Wing of school building,
our class found it very exciting. Most of our
classmates enjoyed the lesson very much. All in
all, this activity is an interesting way for
studying. Therefore, I hope we can have more
similar activities.
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Leung Mei Ling 4E(10)
With this experiment, I feel really excited.  Our
group got the best result in the class. It makes
me feel being successful. And, I know more about
the principle of parachute. We need to concern
the velocity of it, the force acting on it and
how to protect the egg well by other material. I
found that reducing the landing velocity is
really important for protecting the egg.
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 In my group, all the members are very nice and
responsible in doing this project. We discussed
together and had some different ideas, and then
we tried them all. Finally, we accepted the best
one. The feelings are so funny and happy. I am so
glad to finish the project. I think doing a
project is good for me to study!gtwlt
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The End