PSLE 2009 - Science

[ryutotamano.012604hotmail.012604com]

atutor2001:

caroline3sg:

kohjl

thank you.

There is one question about which can travel a longer%20distancein a desert, lizard & snake.

My girl's ans sounds logical but I worry the way she phrased it.

2 reasons (my own words, but her meaning:)
1) snake has no legs, there is frictional force when gliding on the (hot - not sure this word was mentioned in her ans or not) sand.

Personally, I think the longer body also plays a part on its contact on larger surface of the sand.

2) lizard uses front legs to run, hind legs to push it faster. Faster must be linked to longer distance, but don't know / didn't state.

This is amazing! Are they kidding by setting such question? The key words is \"longer distance\".

Are they testing adaptation for heat? I remember snake moves under the sand in the desert to shield from the hot sun. If that is the case, then it should be snake because lizard cannot move under the sand.

Hi Kohjl Jr, what is your take?

Hi I am new here. I am a sec 3 student. Just wondering, what does tavel a longer distance mean? It could also mean who has a greater stamina. This question is testing on adaptations, but I cant identify which one.

[MummyJamie]

Ohh, and what about the second question? The mouldy bread one? Is it water only?

[acelancer]

MummyJamie:

Ohh, and what about the second question? The mouldy bread one? Is it water only?

i put water only but i think it's oxygen and water

[Tang]

hot_chocolate:

my answer for the pot/kettle question was: there is less contact between the surface of kettle b(the one with air spaces) compared to kettle a( the one without air spaces) thus, heat travels more quickly to the kettle a than b, causing the water in it to boil faster.


is my answer correct? I didn't mention that air is a good conductor of heat. :frustrated: yikes!!!

Hi Hot_chocolate,

Your answer is quite the same as what is given here:

http://pslescience.blogspot.com/

Instead of 'heat travels more quickly', it states that 'Pot A gained more heat' - more contact.

[Hello]

i wrote oxygen and water.

[MummyJamie]

acelancer:

MummyJamie:

Ohh, and what about the second question? The mouldy bread one? Is it water only?

i put water only but i think it's oxygen and water

I wrote oxygen&water but googling it doesn't work..

[caroline3sg]

what is the exaxt question on the bread mould?


Definitely not water only.

[yjmama]

My DD answered as water and oxygen

[acelancer]

at first i put oxygen and water then i kei kiang go change my ans.

[Hello]

What are the need(s) for a bread to turn mouldy?


(A)Oxygen
(B)Can’t remember
Water.

Its something like that.