Q&A - PSLE Science

[Way2GO]

verykiasu2010:

the answer should be 'b'


it is impossible for 'c' to happen because it is impossible to retain the same brightness or to achieve reflection from infinite distance (the line plateauing means it is reflected from infinite distance, which is impossible).

the reflection must end at some distance because the further the light source is, the more the light will be dispersed along the way, hence eventually zero light reflected

The question said A,B, C were plotted results, not imaginary.
It was a trick question huh?

While I agree with you that it is not possible to obtain the same brightness over infinite distance,
for our understanding on examiners' expectations,
Are P6 students expected to analyse and draw a conclusion from the graphs
or are they expected to extrapolate beyond what's shown?

[verykiasu2010]

Way2GO:

verykiasu2010:

the answer should be 'b'


it is impossible for 'c' to happen because it is impossible to retain the same brightness or to achieve reflection from infinite distance (the line plateauing means it is reflected from infinite distance, which is impossible).

the reflection must end at some distance because the further the light source is, the more the light will be dispersed along the way, hence eventually zero light reflected

The question said A,B, C were plotted results, not imaginary.
It was a trick question huh?

yes plotted, based on readings taken from the light sensor measuring the reflection. a good reflective material would be able to reflect the light over (or to) a longer distance, tio bo ?

answer 'c' is just to trick and confuse, not unusual. it is an impossible material to have property to reflect an infinite distance

[Way2GO]

verykiasu2010:

Way2GO:

[quote=\"verykiasu2010\"]the answer should be 'b'


it is impossible for 'c' to happen because it is impossible to retain the same brightness or to achieve reflection from infinite distance (the line plateauing means it is reflected from infinite distance, which is impossible).

the reflection must end at some distance because the further the light source is, the more the light will be dispersed along the way, hence eventually zero light reflected

The question said A,B, C were plotted results, not imaginary.
It was a trick question huh?

yes plotted, based on readings taken from the light sensor measuring the reflection. a good reflective material would be able to reflect the light over (or to) a longer distance, tio bo ?

answer 'c' is just to trick and confuse, not unusual. it is an impossible material to have property to reflect an infinite distance[/quote]solli, please see my edited post.
you replied as I was editing.

[verykiasu2010]

Way2GO:

verykiasu2010:

the answer should be 'b'


it is impossible for 'c' to happen because it is impossible to retain the same brightness or to achieve reflection from infinite distance (the line plateauing means it is reflected from infinite distance, which is impossible).

the reflection must end at some distance because the further the light source is, the more the light will be dispersed along the way, hence eventually zero light reflected

The question said A,B, C were plotted results, not imaginary.
It was a trick question huh?

While I agree with you that it is not possible to obtain the same brightness over infinite distance,
for our understanding on examiners' expectations,
Are P6 students expected to analyse and draw a conclusion from the graphs
or are they expected to extrapolate beyond what's shown?

reflective properties of materials is within the scope of PSLE science. No ?

the question requires the student to draw conclusion. no need to extrapolate. they need to ask this : which one can reflect the longest distance? the red herring is the one with infinite distance

[Studious Alien]

verykiasu2010:

the answer should be 'b'


it is impossible for 'c' to happen because it is impossible to retain the same brightness or to achieve reflection from infinite distance (the line plateauing means it is reflected from infinite distance, which is impossible).

the reflection must end at some distance because the further the light source is, the more the light will be dispersed along the way, hence eventually zero light reflected

Thanks for explaining the question and your answer to us. Your assistance is very much appreciated. :thankyou:

[verykiasu2010]

Studious Alien:

verykiasu2010:

the answer should be 'b'


it is impossible for 'c' to happen because it is impossible to retain the same brightness or to achieve reflection from infinite distance (the line plateauing means it is reflected from infinite distance, which is impossible).

the reflection must end at some distance because the further the light source is, the more the light will be dispersed along the way, hence eventually zero light reflected

Thanks for explaining the question and your answer to us. Your assistance is very much appreciated. :thankyou:

all the best for the PSLE !

watch out for the *wicked* tricks in the answer choices .... hehe

[G Tan]

elkniwt:

Hi,


Like to check if mushrooms are micro-organisms?

The links below seem to indicate they are :
http://archives.microbeworld.org/microbes/fungi/

But aren't micro-organisms microscopic? :?

Asked this based on this qn from RGS :
http://i47.tinypic.com/e83mn5.jpg\">

TIA.

The answer is 1. Mushroom is a mould not microorganism

[G Tan]

Robertpattinsonidle:

http://i46.tinypic.com/xp37uf.jpg\"> pls help.

amswer is 1

[paranoid]

http://i47.tinypic.com/10wqwd2.jpg\">


Please help with this question from St Hilda's Prelim. Thanks.

[G Tan]

paranoid:

http://i47.tinypic.com/10wqwd2.jpg\">


Please help with this question from St Hilda's Prelim. Thanks.

answer is 3