Presentation is loading. Please wait.

Presentation is loading. Please wait.

1.Title 2.Content 3.Materials used 4.Design 5.Application of physics principles 6.Results of experiment 7.Improvement 8.Conclusion and discussion 9.Comments.

Similar presentations


Presentation on theme: "1.Title 2.Content 3.Materials used 4.Design 5.Application of physics principles 6.Results of experiment 7.Improvement 8.Conclusion and discussion 9.Comments."— Presentation transcript:

1

2 1.Title 2.Content 3.Materials used 4.Design 5.Application of physics principles 6.Results of experiment 7.Improvement 8.Conclusion and discussion 9.Comments of group members

3 a.Plastic bag b.Thread c.Doll d.Sponge e.Cotton e. b. a. c. d.

4 The egg is placed inside the doll so that the sponge and the cotton inside the doll can be used to protect the egg. The plastic bag is used to increase air resistance.

5 We use a plastic bag to increase air resistance so that the net downward force acting on the parachute is reduced. By F = ma (F =net force = weight – air resistance) Since F is reduced, the acceleration is reduced ( a < g ). As the parachute accelerates, the air resistance also increases, at last, the weight of the parachute is balanced by the air resistance, the net force acting on it is zero and it falls with terminal speed. As a result, its velocity is greatly reduced, the kinetic energy of it when it lands on the ground is also reduced so that it is safe for the egg to land and it will not break on landing.

6 We also use a lot of cotton and sponge to reduce the bombarding force acting on the doll by the ground when it lands on the ground. (By Newton’s third law of motion, when the parachute hits the ground, there is a reaction force acting on the parachute by the ground) 0 t / s v / m s -1 parachute opens terminal speed

7 The parachute landed safely when it fell from the 4 th floor in New Wing of school building onto the playground. The egg inside the parachute did not break on landing. The time for the egg to land on the ground was around 5 seconds. The weight of the parachute was around 100 g.

8 The surface area of the parachute should be increased so it can trap more air. The shape of the parachute should be symmetrical so that the parachute can fall in a straight line. The weight of the parachute should be decreased in order to attain the terminal speed faster and fall slower. The appearance of the parachute can be more attractive by using colourful materials.

9 The egg inside the parachute is just like the skydiver in a real parachute. The egg inside the parachute did not break and this indicates that skydiver in a real parachute can land on the ground safely. The parachute can reduce the speed of the skydiver from about 60ms -1 to 3m -1 which is safe enough for him to land.

10 Fong Ting San 4E (24) This is the first time that I can apply my knowledge learned from the Physics lessons to my daily life. During this project, I needed to make a parachute with my group members. At the beginning, it was quite difficult since I haven’t done anything like this before. Fortunately, due to the cooperation of my group members, the project was quite successful and I learned a lots from it. Lai Long Him 4E (25) I learn much knowledge from this project, I now know how to make a parachute that can successfully and smoothly fall down from a certain height and remaining safe, and all this knowledge is related to Physics. Apart from the enhancing of Physics knowledge, I also learn how to cooperate with others so as to finish a project with work being done efficiently.

11 Lam Ka Wai 4E (27) After doing this assignment, I think I have learnt quite a lot of things. The most important thing is that our team misunderstood the rule of the assignment about the landing speed of the parachute: we thought the greater the speed, the better the score it would be. We had this idea because we were not concentrated enough in Physics lessons. That is a great shame! Li Wa Yee 4E (33) Since we want to make a perfect parachute, each part of it must be designed carefully. This is not easy to do. We should adjust the weight and the size of the parachute carefully. In this project, we had many problems. For example, to find a place that the height is great enough to test the parachute. Also we needed to think about how to make the design more attractive without affecting its function and its weight. I think this is quite challenging.

12 Ng Chung 4E (35) During this project, I had learned more about force. I needed to design the structure of the parachute and think about how to reduce the net force during falling. The most difficult part of this project is how to design the parachute which can allow the egg to land safely. Finally, I think the project is very successful.


Download ppt "1.Title 2.Content 3.Materials used 4.Design 5.Application of physics principles 6.Results of experiment 7.Improvement 8.Conclusion and discussion 9.Comments."

Similar presentations


Ads by Google