Tuesday, August 01, 2006
back from sohmin's house!
we tried out various hairstyles
big thanks to her for french braiding our hair x)
and perming mine. lol
i tied lynn's hair!
and she looked totally fresh
too bad she aint photogenic with tht hair ):
but when sohmin uploaded th photos, everyone will see how pro she is!
not to forget me too ;p
had chinese, totally shut off
wasnt paying attention
think it was sth bout writin an argumentative essay; lun zheng lun ju lun suo?
whatever~
thn math
did revision i think...
social studies
argh totally forgot how different source a is from b HAVE TO INCLUDE BOTH SIDES!!!
and you have to make an inference, THN u support
ah i suck
didnt do really well for my ss test too
7/13
well at least i passed
considering th fact tht i didnt really study on deterrence!
i was oh so diplomatic ):
physics, wins the most interesting lesson of the day!
learnt about the electromagnetic spectrum
origin
1. caused by oscillating electric charges, generating electric fields
2. vibrating movements, which causes magnetic fields to be generated and cause it to move like a wave
nature
1. they are transverse waves
2. speed at 3x10^8 in vacum, like light rays, they undergo reflection and refraction too!
meaning it would bend? haha duno, but i know when it enters another medium it will slow down
And!! ***the frequency is constant! ;D
classification and application
the lower the frequency, the longer th wavelength; radio waves
`used in television broadcast and radio communication
`(they are short) sent out from transmitter, relected by ionosphere , thn picked up by th antenna
mircowaves.
`used in satellite transmission for tv too! and telephone x)
`useful for places which are mountainous since thy are isolated and transmission by cables and wires = not feasible
infrared radiation
`household appliances; ear thermometer, remote controller
`security system (night vision) prevent unauthorised intrusion
`navigation during foggy weather
visible light
red travels the fastest, violet slowest
faster= refract lesser, slower, refract more
bend bend away!
***
`used in telecommunication thru the use of optical fibres
`medical fields; laser sugery, correction of myopia
ultraviolet radiation
`produce vitamine D in body
`sterilise dirty water
`detect counterfeits
`medial field; treatment of jaundice
x-rays radiation
`used in medical! and diagnostic tools for detection of fractures/ tooth decay
`also in engineering; detection of foreign objects in aircrafts lest they explode
gamma rays
` emits from radioactive atoms cosmic rays, nuclear explosions
`medical field; chemotheraphy and sterlisation of surgical tools
high frequency=high energy
