Q&A - P5 Science

[sleepyqueen]

wahwah:

Nebbermind:

[quote=\"wahwah\"]Hi,

Need help with following science question.

Why are there lines formed in ice cubes?
How can we make crystal clear ice cubes?

This one P5 qn??!! :yikes:

Yes, P5 question. Anyone can help?[/quote]Too chim even for me. :nailbite:
I do not know the answer till i read the answer post here.
But our primary school science standard so high these days?

[zinc6539]

atutor2001:

SAHMwith2boys:

Hi all


Need help on the below question, suppose to choose True (T), False (F) or Not Possible to tell (NP) for the question:

Some cells cannot reproduce to form new cells.

The word \"Some\" means \"more than one\". However, I only know that red blood cells cannot reproduce. Unless I also include those dead cells found in nail and hair, then I can say that red blood cell and dead cells cannot reproduce and the answer is \"True.\" Or I interpret \"some\" to mean more than 1 cell though they are of the same kind.

I believe that the setter wanted the answer to be \"True\" but was not too sure if there are other living cells (besides red blood cell) that also cannot reproduce and conveniently use the word \"some\" in the question.

Appreciate anyone sharing your insight into this. Thanks.

I did this question with my ds too. The answers I got from searching the internet is that besides red blood cells, nerve cells also cannot reproduce. You can read more http://scienceline.ucsb.edu/getkey.php?key=1710

[zinc6539]

Question 44 from P5 Science 2011 SA1 Nanyang:

http://img.photobucket.com/albums/v187/veron/Capture.jpg\">

Suggested answer is: \"100 cubic cm. The space in the tank can be compressed.\"

But I thought it should be 200 cubic cm, because air does not have a definite volume and the air particles will move about freely to fill up the whole tank. Am I wrong?

[atutor2001]

zinc6539:

I did this question with my ds too. The answers I got from searching the internet is that besides red blood cells, nerve cells also cannot reproduce. You can read more http://scienceline.ucsb.edu/getkey.php?key=1710

Hi zinc6539
Thank you very much for sharing this very interesting piece of information. Learn something new today.

[atutor2001]

zinc6539:

Question 44 from P5 Science 2011 SA1 Nanyang:

http://img.photobucket.com/albums/v187/veron/Capture.jpg\">

Suggested answer is: \"100 cubic cm. The space in the tank can be compressed.\"

But I thought it should be 200 cubic cm, because air does not have a definite volume and the air particles will move about freely to fill up the whole tank. Am I wrong?

I agree with you.

[verykiasumummy]

zinc6539:

Question 44 from P5 Science 2011 SA1 Nanyang:

http://img.photobucket.com/albums/v187/veron/Capture.jpg\">

Suggested answer is: \"100 cubic cm. The space in the tank can be compressed.\"

But I thought it should be 200 cubic cm, because air does not have a definite volume and the air particles will move about freely to fill up the whole tank. Am I wrong?

yup it should be 200cm3. air does not have a definite volume so it can space out to occupy the capacity of the tank..

its almost the same question as discussed for p4 sci...

[papilion]

Hello, below is a question on condensation and properties of air.

I'm not sure whether my answers are correct. :roll:
question (a) has more marks weightage (2 marks) than question (b) (1 mark.
I need to know whether my answers are correct, insufficient info or need further elaboration.
Sometimes what the tutor/tutition centre teach the kid is not appropriate, cause of certain key words missing ? Please help. thanks :boogie:
http://i49.tinypic.com/108is6v.jpg\">
My answers
(a)\tWhen the cold water touches its surface, the air in the flask is being pushed into the delivery tube causing the water level to move downwards.
(b)\t When the air in the flask is cooled down, it contracts and this compressed air causes the air in the delivery tube it moves into the flask, so the water level moves upwards.
:gloomy:

[papilion]

sorry I don’t know how to post the pic, trying again

[verykiasumummy]

papilion:

Hello, below is a question on condensation and properties of air.

I'm not sure whether my answers are correct. :roll:
question (a) has more marks weightage (2 marks) than question (b) (1 mark.
I need to know whether my answers are correct, insufficient info or need further elaboration.
Sometimes what the tutor/tutition centre teach the kid is not appropriate, cause of certain key words missing ? Please help. thanks :boogie:
http://i49.tinypic.com/108is6v.jpg\">
My answers
(a)\tWhen the cold water touches its surface, the air in the flask is being pushed into the delivery tube causing the water level to move downwards.
(b)\t When the air in the flask is cooled down, it contracts and this compressed air causes the air in the delivery tube it moves into the flask, so the water level moves upwards.
:gloomy:

sorry papilion, both a and b will be marked wrong..

a) when cold water is poured on the outer surface of the flask, the flask loses heat and contract, hence the air inside the flask moved to occupy more space in the glass delivery tube, causing the water level in the glass delivery tube to go down.

b) when the air inside the flask loses heat and contracts, the air will occupy less space and therefore the water in the glass delivery tube will then go up to occupy the space once occupied by the air.

[Jamesbond]

http://i47.tinypic.com/6ypjli.jpg\">


Pl help my ds answer this....