Q&A - P3 Science

[underthesea]

ET-PH:

Hi, I would think the answer is A. In this experiment, the water level has raised to 125ml from 100ml, the stone has occupies the space in the water. The experiment do not show or prove that the stone has a definite volume, though the stone (a solid) has a definite volume. Hope I am right.

I have asked a few other parents and also asked dd to check with her teacher. The correct answer should be \"B - the stone had definite volume\".
We only say the stone occupies space if water spill out from the beaker, ie the stone replaces the space taken by the water.

[ET-PH]

I m sorry to give you the wrong answer. I really can't think why the answer is \"the stone has a definite volume\". The stone has a definite volume (without the experiment), but in the context of this experiment, the water raised from 100ml to 125ml basically shows that the water has been displaced by a matter which occupies space. :?

[ChiefKiasu]

ET-PH:

I m sorry to give you the wrong answer. I really can't think why the answer is \"the stone has a definite volume\". The stone has a definite volume (without the experiment), but in the context of this experiment, the water raised from 100ml to 125ml basically shows that the water has been displaced by a matter which occupies space. :?

We will quickly come to realize that Primary School Science is about using the right terms for the specific question. \"Definite volume\" is a term the kids learnt in school to refer to solid matter that has a definite shape (as opposed to liquids or gases). All matter occupies space. So while in common terms the displacement of water is due to the stone taking up \"space\" in the water, the correct answer is that the experiment demonstrates that the stone has a definite volume.

[atutor2001]

ET-PH:

I m sorry to give you the wrong answer. I really can't think why the answer is \"the stone has a definite volume\". The stone has a definite volume (without the experiment), but in the context of this experiment, the water raised from 100ml to 125ml basically shows that the water has been displaced by a matter which occupies space. :?

Hi ET-PH

The experiment shows that the stone has a \"definite volume\" because the raised water level REMAINS at 125 ml.

If the stone does not have a definite volume, then the water level will not stay at 125 ml but will move up and down above the 100 ml mark.

[elkniwt]

Hi,


Need help in this Qn. Henry Park P4 2009 SA1 Paper, Qn 20.

http://www.orlesson.org/orp/09Sc/P4-09-Sc-SA1-HenryPark.pdf

The answer given is 4. My dd's ans is (2). I also think that 2 is correct. Shouldn't the air in X decrease in volume causing the ink to move towards X ??? :?

Please help. Thanks!

[tutormum]

elkniwt:

Hi,


Need help in this Qn. Henry Park P4 2009 SA1 Paper, Qn 20.

http://www.orlesson.org/orp/09Sc/P4-09-Sc-SA1-HenryPark.pdf

The answer given is 4. My dd's ans is (2). I also think that 2 is correct. Shouldn't the air in X decrease in volume causing the ink to move towards X ??? :?

Please help. Thanks!

Your answer is correct as the cold water causes the volume of air to decrease (matter contracts when cold and expands when hot). FYI, can't trust answer sheets as mistakes abound.

[Muffins]

hi tutormum, first, the cold water will make a little of the bottle contract, making the droplet move towards Y. Then,l after about 1 minute, the air inside X will contract, causing the droplet to move towards X.

[elkniwt]

Thanks a lot!, tutormum & Muffins.

[Muffins]

you're welcome...

[tianzhu]

Muffins:

hi tutormum, first, the cold water will make a little of the bottle contract, making the droplet move towards Y. Then,l after about 1 minute, the air inside X will contract, causing the droplet to move towards X.

Hi muffin

I am wondering if you’ve ever carried out an experiment which shows that the ink droplet move to the right slightly first, then towards X when flask X is immersed in cold water

For primary science, is it necessary to elaborate that the ink droplet moves slightly to the right first? I think this information is not covered in primary textbook.

Best wishes