My Physics Tuition Lesson

Today nothing special happen. And I guess smth special must be happen to kc sp soony them. Jealous o.o . I woke at 4pm and go straigh to ( whitout taking bath ) online. then, until my phone's reminder reminded me about the time (15 mins left before my tuition.) , in 10 mins i clean up myself and drift there. ho cai my tuition centre only located at greenlane, which is not so far from my house. By the time i reach there, my physics teacher already started discussing questions. Luckily there are still an empty seat left at the first row, just beside Ee Ling. ( I think they purposely left it for me as I am the VVIP there, The king of late ) and I could never remember I enter the room before the class get start. 

Okay. Now, ( bio kaki siam ) lets talk about physics! hehe. I know I'm always unavailable because of my tuitions.( the cameron trip the same reason too? =p) 

Today the teacher teaches us about Sources of Musical Sound. He used 4 types of instrument to demo how sound waves are produced.

 My physics teacher was performing musical instrument? Nawhh. He just blow it. it is a close pipe instrument. and I was sitting at the first row. just right beside him. torture my ears LOL

drawing the fundermental mode of close pipe.

length of close pipe, fundamental mode of vibration. A stands for Antinode and N stands for Node the waves will reflect when they reach the Node
a close pipe instrument which cost rm 1 and you can get it in melaka or cameron. ( usually only tourists will buy it)

Now he took out his guitar in oder to teach us string instrument. 

plucking his guitar to produce sound wave. But his guitar only left 4 strings. another 2 still there but patah already. see the string hanging there? ( sorry I just use my phone that doesn't hv autofocus ,not DSLR XD)

see?only 4 strings left. he asked who can play gitar come out and show 2 notes of same tone but higher an octave. I can but I was too paiseh to do so. don wanna show myself too aften. later my admirer increase again. Muahaha XD

f=v/lamda. where v here = square root T/miu. (velocity of sound, approximately 330-340m/s) 
when you pluck a string it will form a stationary wave, like this. l = length of string = lamda/4 .
Antinode and Nodes.

Untill now I just realize that most of the instruments are open pipes.And you can only found closed pipe instrument at those deserted places. This is because closed pipe can only produce odd number harmonics,so it can't produce most of the tones that a piano can play. If you are interesterd in this topic , ( and you are a bio student), pls kindly visit pcghs head office and find Miss Ng Choi Leng to change your subjects. 
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Physics 10000 years old