*Design of parachute*

1. Physics Project *Design of parachute*

2. Content • 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

3. Materials used • 1. Plastic rubbish bag 2. Sponge

4. Design • The plastic bag is the major material for making the parachute and it can increase the air resistance. • The egg is put into the sponge ball and it can protect the egg.

5. Application of physics principles • By F = ma, • The plastic bag can increase air resistance so that the net downward force acting on the parachute decreases. Since F decreases, the acceleration also decreases. So the parachute lands more slowly onto the ground. Its landing velocity is greatly decreased when it lands on the ground. The kinetic energy also decreases so that it is safer for the egg to land and it will not break easily.

6. Results of experiment • We threw the parachute we designed from 4th floor in our school building to the ground. • It took 10.72 s to fall to the ground. • And the egg did not break. The design of sponge was very successful to protect the egg but more should be done to lower the speed.

7. Improvement • We should increase the surface area of the plastic bag so as to increase air resistance. The parachute can then move down slowly. • We should reduce the weight of the parachute. • We should throw the parachute down in a good way.

8. Conclusion and discussion • A parachute shouldbe made from thin, lightweight fabric, support tapes and suspension lines. • A parachute can effectively make things land safely. In this case, the egg had not broken. • The surface of the parachute is very important to make it land slowly. • The weight of the parachute should not be too large.

9. Comments {1} • Lau Ka Ki 4C (26) • In physics lesson, we need to make a parachute. We used plastic bag and sponge to make it. Sponge was used to protect the egg. When we tried to throw the parachute, the classmates were very excited. It took about ten seconds for the parachute to fall down. I think this result is quite good. • Wong Chu San 4C (37) • The project was very suceessful. All my classmates worked hard.But we have failed many times in the trials. It was lucky thatour egg did not break in the test. This project makes me know more about physics. I hope that we may have other project in the future. I will be more active in the next project if we really have one.

10. Comments {2} • Chan Wai Kit 4C (19) • In this physics project, I learned a lot about parachute. My major job is to make the powerpoint so I learned more about the parachute in searching for information. I think this is very useful for my life. Although the parachute is not designed very well, I feel happy in this project. Because I can do all we can with my group members and have our friendship strengthened. • Law Kwok Wai 4C (28) • At first, the parachute we made was a failure, so I felt very unhappy. But on the second time ,we were successful. I think making parachute is so difficult as it is necessary to protect the egg. But after we had made some improvement, wesucceeded. • Itis still not very good but I like what we have done.

11. Comments {3} • Wong Siu Yau 4C (39) • At the beginning of this project, I have asked the F.5 students how to do it well so I think we can finish it easily. But their suggestions were not very useful so we tried it ourselves. Although it is difficult, we can still finish it in time. I feel very happy. And friendship of our group members are strengthened.

12. Group members • 1. Chan Wai Kit (19) • 2. Lau Ka Ki (26) • 3. Law Kwok Wai (28) • 4. Wong Chu San (37) • 5. Wong Siu Yau (39)

13. ～～ The End ～～