Q&A - P4 Science

[jedamum]

Smartmummy

Thanks for clarifying.
Will let my boy know.

[verykiasumummy]

tayobus:

http://i49.tinypic.com/2aont0.jpg\">


Dear All,
My child is doing the past year paper and when come to the above question, he said not his level topic and he found out from the PSLE Science guide book it is upper block topic. Can anyone advise does your P4 child learnt the above? How do your child answer the above? By the way, this is taken from Nan Hua Pri SA2 2011 paper.

:thankyou:

hi,

to clarify, this is an application question applied from topic plants system. (function of stem is to carry water n mineral salts to all parts of the plant)

Ans :
a) the water level in both cups will decrease.
b) some parts of the flower will turn red while some parts will turn blue.
c) the water-carrying tubes called xylem caused the flower to change its colour.

[jedamum]

hihi,

want to ask...
when heated, metal expands, so when it expands, does it become heavier?
thanks.

[PiggyLalala]

jedamum:

hihi,

want to ask...
when heated, metal expands, so when it expands, does it become heavier?
thanks.

I think the answer is no.

[seletar]

Key words - MASS does not change!

[Jamesbond]

http://i48.tinypic.com/30j5qa8.jpg\">

Questn from SGCS SA2 2011

Need answer for (c)...

Can it be...
1) Material of the rod
or
2) Amount of butter..

Pl confirm and explain....Thx.

[atutor2001]

Jamesbond:

Need answer for (c)...

Can it be...
1) Material of the rod
or
2) Amount of butter..

Pl confirm and explain....Thx.

The aim is to find out how the \"RATE of melting is affected\" when the length of the rod is changed.

If we change the amount of butter and use special equipment to measure the amount of butter melted together with the time it takes, we can still find the \"rate of melting\". That is, we will still be able to arrive at a conclusion as to how the length will affect the rate of melting. However, it is very difficult to conduct such an experiment.

In my opinion, \"material of the rod\" is the answer as it is impossible to come to the conclusion we need, if the materials of the rods are not the same.

I think it is difficult for Pr students to understand why the amount of butter can be changed and yet we can still come to the conclusion we need.

[Jamesbond]

atutor2001:

Jamesbond:

Need answer for (c)...

Can it be...
1) Material of the rod
or
2) Amount of butter..

Pl confirm and explain....Thx.

The aim is to find out how the \"RATE of melting is affected\" when the length of the rod is changed.

If we change the amount of butter and use special equipment to measure the amount of butter melted together with the time it takes, we can still find the \"rate of melting\". That is, we will still be able to arrive at a conclusion as to how the length will affect the rate of melting. However, it is very difficult to conduct such an experiment.

In my opinion, \"material of the rod\" is the answer as it is impossible to come to the conclusion we need, if the materials of the rods are not the same.

I think it is difficult for Pr students to understand why the amount of butter can be changed and yet we can still come to the conclusion we need.

Thank you very much atutor2001......

[Jamesbond]

Hi Have another doubt…


If salt is added to ice, how will it affect the melting point and freezing point…Can somebody give me the answer…

If I am correct…the melting point is lowered…

Also…when salt is added to ice, will the ice melt faster or slower?

Pl help…

[atutor2001]

Jamesbond:

Hi Have another doubt...


If salt is added to ice, how will it affect the melting point and freezing point...Can somebody give me the answer...

If I am correct...the melting point is lowered...

Also...when salt is added to ice, will the ice melt faster or slower?

Pl help...

These are the effects when salt is added to water :

1. Melting point / Freezing point will be lowered.
2. Ice will melt faster.
3. Water will take a longer time than usual to freeze.
4. Boiling point will be raised.
5. Water will take a longer time than usual to boil.

Best not to explain why ice melt faster. It is too complex.