Q&A - P3 Science

[Tang]

PlasmaStorm:

Full.Cream:

[quote=\"MdmKS\"]Got this problem from my P3 child worksheet.


A conical flask contain some water and a plant with its roots submerged in the water. A stopper is fixed at the mouth of the flask holding the stem of the plant with its leaves hanging outside the conical flask. Sorry, I am not sure how to upload the image file here.
Question : how to reduce the rate of water being absorbed by the roots? Give 2 methods, without changing the setting of the experiments.

T!A

for plants, i believe the answers will always revolve around water, air & sunlight. the answer is probably to reduce the (i) sunlight & (ii)CO2 which will slow down photosynthesis (sun + CO2 + water = starch). Not sure how this can be achieve, tho. :oops:

Hi I'm a P6 student and I think that if you cut the leaves, there will be less photosynthesis and so it will use less water.

Hope this helps!

From: PlasmStorm

(Formerly, kohjl Jr )[/quote]
Since you have cut the leaves, I shall cut the stems / branches to remove some of the water carrying tubes.

[Muffins]

tianzhu:

Dharma:

[quote=\"tianzhu\"]Hi, Dharma and Full.Cream


There are some missing information in one of my previous post.Here is the revision.Please follow this link.

http://www.oldschool.com.sg/index.php/module/PublicAccess/action/Wrapper/sid/a1d5550a35132f7d768a9cd73d70318e/mcq_id/15658

I am sorry for the inconvenience.

SorryTianzhu, I missed this out earlier.

When the cardboard is removed, the light brown gas will spread to fill up the whole of the jar and flask.

This tells us that
1.\tGas has no definite shape – it takes up the shape of the container that it is in.
2.\tGas has no fixed volume – it spreads to fill up the space in the flask in addition to the space it has already filled in the jar.

The answer is Option C – B & C

# Although air can be compressed but the experiment does not demonstrate this property of air.

Hi Dharma

I’ve been looking at this question for quite a number of times. It’s a pretty interesting one.

The first diagram shows the brown gas in a jar.
The second diagram shows the brown gas occupying the volume of the jar as well as the flask. It expands.
From the first diagram, the brown gas take up a smaller space in the jar .Therefore it can be compressed. After the cardboard is removed, it expands to take up the combined capacities of the jar and flask.

So this experiment shows that air has no definite shape, volume and is compressible. What’s your view on this?[/quote]Hi Tianzhu, in your second post, you say that the air expands to take up the VOLUME of the two jars but this does not show that air has a definite volume. That is true, but in oldschool.com, after seeing the diagram, it is seen that the air rises to take up the space inside the jar, not the volume, basically rise to fill up the SPACE inside, and not the volume. And the cardboard covering COMPRESSED the air, so when the flask was initially put on top of the jar, the gas did not rise up to fill the space in the jar...

So I think that the correct answer should be A and B.

[Muffins]

MdmKS:

Got this problem from my P3 child worksheet.


A conical flask contain some water and a plant with its roots submerged in the water. A stopper is fixed at the mouth of the flask holding the stem of the plant with its leaves hanging outside the conical flask. Sorry, I am not sure how to upload the image file here.
Question : how to reduce the rate of water being absorbed by the roots? Give 2 methods, without changing the setting of the experiments.

T!A

Hi MdmKS, I think you could reduce the amount of water in the set-up, and chop off the roots. This changes the plant, but not the setting of the experiment. Settings of an experiment mean that the plant should not be moved to a different location...

[nani]

Here is a question found in a p3 science bk:

Question: What is the similarity between a robot and a baby?
My son's ans:Both have systems.
Teacher's ans: Both have hands and legs.
Which is a better ans? Pls help,thnx!

[Tang]

nani:

Here is a question found in a p3 science bk:

Question: What is the similarity between a robot and a baby?
My son's ans:Both have systems.
Teacher's ans: Both have hands and legs.
Which is a better ans? Pls help,thnx!

Both can move.

Both can respond to changes.

Answer in terms of living things and non-living things.

Based on above, the teacher's answer \"Both have hands and legs.\" is better - related to \"move\" and \"respond to changes\".

\"Systems\" is not so appropriate as this Topic is taught so much later than the Topic \"Living and Non-Living Things\". I believe for this question, a picture of the robot and the baby is given. We also cannot see any \"Systems\" based on the picture given.

[Joy]

Hello all


Can I just post one mcq before my girl exam which is tomolo?

Su placed a bag of ice cubes weighting 58g on an electronic scales.what will the reading on the scale be when all the ice cubes in the bag has melted.
1exactly 58g
2slightly less than 58g
3 slightly more than 58g
4 not possible to tell/.

ans given is 3

can someone explain.thanks

[elkniwt]

Hi,


Like to check with regards to Nan Hua 2008 SA2 Science Q8

Which one of the following group of animals has the function of the outer coverings matched to it wrongly?

Animal/Outer Body Covering/ Function
1) Bird / colour feathers / camouflage with the surrounding
2) Insect/ hard outer covering/ protects its body
3) fish/scales / propel it in swimming
4) mammal/fur/keep its body warm

The ans given in the ans key is 2. My dd's ans is 3 and I kinda feel that 3 is more correct. Anyone there can shed light on this question? Thanks and really appreciate. :lol:

[atutor2001]

Joy:

Hello all


Can I just post one mcq before my girl exam which is tomolo?

Su placed a bag of ice cubes weighting 58g on an electronic scales.what will the reading on the scale be when all the ice cubes in the bag has melted.
1exactly 58g
2slightly less than 58g
3 slightly more than 58g
4 not possible to tell/.

ans given is 3

can someone explain.thanks

Hi Joy

The answer is 3 because water vapour from the surrounding air will condense on the external surface of the bag. This additional water will increase the weight indicated on the weighing scale. :lol:

[atutor2001]

elkniwt:

Hi,


Like to check with regards to Nan Hua 2008 SA2 Science Q8

Which one of the following group of animals has the function of the outer coverings matched to it wrongly?

Animal/Outer Body Covering/ Function
1) Bird / colour feathers / camouflage with the surrounding
2) Insect/ hard outer covering/ protects its body
3) fish/scales / propel it in swimming
4) mammal/fur/keep its body warm

The ans given in the ans key is 2. My dd's ans is 3 and I kinda feel that 3 is more correct. Anyone there can shed light on this question? Thanks and really appreciate. :lol:

Hi elkniwt

I share the same answer as your daughter. I think there is printing error in the answer key.

[MdmKS]

Muffins:

MdmKS:

Got this problem from my P3 child worksheet.


A conical flask contain some water and a plant with its roots submerged in the water. A stopper is fixed at the mouth of the flask holding the stem of the plant with its leaves hanging outside the conical flask. Sorry, I am not sure how to upload the image file here.
Question : how to reduce the rate of water being absorbed by the roots? Give 2 methods, without changing the setting of the experiments.

T!A

Hi MdmKS, I think you could reduce the amount of water in the set-up, and chop off the roots. This changes the plant, but not the setting of the experiment. Settings of an experiment mean that the plant should not be moved to a different location...

Hi all, thanks for making this problem \"stay alive\" . Tomorrow is son's Sci exam and till now the teacher still have no chance to go thru the answer with them yet due to the long break follow by exam. The paper has been guided self-marked and done half way.