it is easier to explain by using diagram

real image


virtual image

Basic definition of virtual image:
An image which cannot be projected/focused onto a screen is called a virtual image.
For mirrors, the image is virtual if it is behind the mirror. (Convex mirror will always produce a virtual image.)
For lens, the image is virtual if it is front of the lens. (Concave lens always produce a virtual image.) or same position as the object
When image is at infinity, the image is virtual.

i hate bio essay part
sure gao2 the question
physic essay part is the best

erm..virtual image is it mean that we cant take out the pic and display it in a screen?

but in cinema that the image can be display and seen on a screen..so it is real?

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Added on November 4, 2008, 3:29 pm

I need help. This one is a really simple question but I don't know how to solve this =/

A brick falls from a height of 10m.
Calculate the time taken for the brick to reach the ground.
This one is past year question - 2007.

add math form 5 ques

Find the smallest term of the geometric progression 27 , 18, 12.... that is less then 2..
how?

why wor?

somehow i feel abit lazy to study today maybe because i study too much in the past few week which make me really stress.

yo shit..i am tryin 2 help u people out there...if u dun wan den keep ur ass shut...btw i am 10x smater then you...any1 gt problem? wei lan jiao's who eva wanna fight wif me???juz leave me ur real add....i'll show to u people d power of double7....u can also fight wif me usin ur brains bcoz m smarter den u people out der....m tryin to help those who need help and if u dun wan a help den ignore that msg u dunks....again to people who reali wan a help..u can contact me and for those who thinks dat this is goin 2 ruin our education system fu*k off bcoz our education system already been ruined by our education minister....

What's the point of taking an exam when you know every exact question that will be tested?

You are only fooling yourself.

And SPM papers are supposed to kept in some safe/lock until the day of the exams itself.

now im figuring out whether to get a correction tape or liquid, or both ~

yeah think so too
really r mrsm got soalan bocor?
or maybe they just got lucky on that exam
bcoz spm is kerajaan meh?
mrsm -> mara?
never heard sbp got leaked question
i stayed on sbp last year
then i quitted

help me do this question.

An unmarked thermometer is used to measure the temperature of pure melting ice, warm water and steam. The lengths of mercury thread in the thermometer for the measurements are 2.5 cm, 6.0 cm, and 12.0 cm respectively. The temperature of the warm water is ?

last day of staying in my class T_T so sad

In a geometric progression, the sum of the first term and the third term is 20 and the sum of the fourth term and the sixth term is 540. Find the common ratio..pls list out the step for me..i stuck

T1 + T3 =20
T4 + T6 = 540

a + ar2 =20
ar3 + ar5 =540

then stuck