eh. im damn scared. lol.

after reading siying's blog.

she study like what 3h plus for 2 chapters?!

then i down here study not even 1 hour finish already. hahha.

okay more than 1hour.

but i managed to cover all lehhh..
sound electricity and changing matter only right!

SOUND.

- D = S x T

- sound is the vibration of particles and a series of waves that move through matter.

- Unit for frequency: Hertz. (Hz)

- pitch is affected by LENGTH, THICKNESS, TENSION.

(wah i keep seeing the word pitch now it looks like a dog's name)

- factors that affect frequency: tension, length, thickness.

- ultrasound is a range of sound above the human range.

(like ultraman! hahaha. stupid blinking red dot on his chest.)

it says "... especially women, can hear above 20 000Hz." :D

sigh, what can i say. hahaha.

oh and its taken by my phone camera, so pardon the blurness.

walao. my mothers CYBERSHOT, 3.2m camera, BLURRER THAN MINE.

disgrace disgrace.

(mines the stupid imode one.)

okay continue.

- used to look at a baby inside the mother's uterus.

- to break down kidney stones.

- ultrasound spectacles help blind people find their way around.

- used to detect tumours.

the last section.

" Ultrasound is used to determine the size, growth rate, sex,
position, due date of delievery, and the number of foetus in a pregnant woman."

they seriously shouldnt put "sex" before "position"..
know what i read it as anot!

"Ultrasound is used to determine the size, growth rate, sex
position, due date of delievery, and the number of foetus in a pregnant woman."

if you cant spot the difference you are quite slow man. hahaha.
walaoo. okay continue.

ELECTRICITY.

SI units:
Voltage: volt (V)
- the measure of how much energy the electrons receive.
Resistance: ohm (Ω)
- property of a material that resists the flow of an electric current through the material.
Current: ampere (A)
- the flow of electrons in one direction in a circuit.

- ammeter connected in series, voltmeter in parallel.
- in series, the current is the same.
- in parallel, current splits.

CHANGING MATTER.
physical and chemical change.

physical.
- no new substances are formed.
- reversible.
eg. change of state, dissolving, change of temperature.
melting ice, dissolving sugar.

chemical.
- new substances are formed.
- irreversible.
eg, combustion, decomposition, rusting.
baking cake, toasting bread.



wah. this is useful k.
those who read before the exam.
you're in luck! hahaha.
these are like the more impt points :D
or so said by ms loo..

okay. i shall go sleep now. 4.27am :D