Q&A - PSLE Science

[Robertpattinsonidle]

charsen:

elkniwt:

Hi,


Need help on this qn from CHS prelim :

http://i46.tinypic.com/1zp03fb.jpg\">

Answer in answer key is (2). dd's ans is (1) ?? (I think ans key is wrong, need some advices. Thanks!) :?:

Hi
Volume of substance b + marbles---->300cm3
Since Substance d can compress,the volume of the substance d should be 700cm3.
cheers

i dont understand the reason behind this. anyone can explain pls?

[elkniwt]

Dear Fat Mama, charsen and Alarmchain,


Thank you so much for your confirmation!! :hugs:

Dear Robertpattinsonidle,

You can take note of the explanations given by Fat Mama, charsen and Alarmchain.

[charsen]

Robertpattinsonidle:

charsen:

[quote=\"elkniwt\"]Hi,


Need help on this qn from CHS prelim :

http://i46.tinypic.com/1zp03fb.jpg\">

Answer in answer key is (2). dd's ans is (1) ?? (I think ans key is wrong, need some advices. Thanks!) :?:

Hi
Volume of substance b + marbles---->300cm3
Since Substance d can compress,the volume of the substance d should be 700cm3.
cheers

i dont understand the reason behind this. anyone can explain pls?[/quote]Hi
Substance B and the marbles have a definite volume.thus,they could not be compressed.Hence,their volume will be always 300cm3.Substance d can be compressed.For example,assume that substance d is air.If there is 700cm3 of air in the bottle and 300cm3 of other substances which has a definte volume,no matter how much volume of air is pumped in the bottle,assuming that the capacity of the bottle is 1litre,the volume of air remains the same as air occupies space.Relate this explantion to the question and you should be able to answer your doubts on the question.

Remember,althogh air can be compressed,it cannot be compressed fully.
Cheers

[charsen]

Robertpattinsonidle:

charsen:

[quote=\"elkniwt\"]Hi,


Need help on this qn from CHS prelim :

http://i46.tinypic.com/1zp03fb.jpg\">

Answer in answer key is (2). dd's ans is (1) ?? (I think ans key is wrong, need some advices. Thanks!) :?:

Hi
Volume of substance b + marbles---->300cm3
Since Substance d can compress,the volume of the substance d should be 700cm3.
cheers

i dont understand the reason behind this. anyone can explain pls?[/quote]Hi
Substance B and the marbles have a definite volume.thus,they could not be compressed.Hence,their volume will be always 300cm3.Substance d can be compressed.For example,assume that substance d is air.If there is 700cm3 of air in the bottle and 300cm3 of other substances which has a definte volume,no matter how much volume of air is pumped in the bottle,assuming that the capacity of the bottle is 1litre,the volume of air remains the same as air occupies space.Relate this explantion to the question and you should be able to answer your doubts on the question.

Remember,althogh air can be compressed,it cannot be compressed fully.
Cheers

[G Tan]

Can someone teach me how to upload a picture to my post

[tianzhu]

G Tan:

Can someone teach me how to upload a picture to my post

Hi

If the question is from top school past years papers, you may just provide a link to the paper highlighting the question number of the particular question you wanted to ask.

http://www.orlesson.org/orp/ScienceExam.html

The steps to insert an image

1) Do a print screen of the portion you want to upload.

2) Edit using Paint. Cut out the portion of the question you want to upload.

3) Save file in pictures

4) Go to Flickr (Free sign up as member) or other storage sites. Upload file. Select medium size. Right click to copy URL of image.

5) Coming back to Kiasuparents forum, click insert image button.

Best wishes

[Fat Mama]

How do you interpret the following sentences


1. The nail attracted the magnet.

2. The nail is attracted to/by the magnet.

Tks

[Robertpattinsonidle]

http://i48.tinypic.com/s3hawl.jpg\"> someone help me with these types of questions. how to understand and what is the explanation?

[pench]

Robertpattinsonidle:

charsen:

[quote=\"elkniwt\"]Hi,


Need help on this qn from CHS prelim :

http://i46.tinypic.com/1zp03fb.jpg\">

Answer in answer key is (2). dd's ans is (1) ?? (I think ans key is wrong, need some advices. Thanks!) :?:

Hi
Volume of substance b + marbles---->300cm3
Since Substance d can compress,the volume of the substance d should be 700cm3.
cheers

i dont understand the reason behind this. anyone can explain pls?[/quote]
Dd wrote this:
Option 1 should be correct(700cm3). Cuz the total volume of the marbles is 100cm3, and that does not include air spaces. Like, duh. Substance b can't be compressed, as well as the marbles. So, obviously, substance d, air, takes up the rest of the space which is 700cm3. Anyway, even if the 100cm3 includes air spaces, the air can be compressed when substance b fills up the space, but in the end substance b and the marbles still take up 300cm3 of the space, and the remaining space is filled by the air. So, 700cm3!!!

[mamago]

pench:

charsen:

[quote=\"elkniwt\"]Hi,


Need help on this qn from CHS prelim :

http://i46.tinypic.com/1zp03fb.jpg\">

Answer in answer key is (2). dd's ans is (1) ?? (I think ans key is wrong, need some advices. Thanks!) :?:

Dd wrote this:
Option 1 should be correct(700cm3). Cuz the total volume of the marbles is 100cm3, and that does not include air spaces. Like, duh. Substance b can't be compressed, as well as the marbles. So, obviously, substance d, air, takes up the rest of the space which is 700cm3. Anyway, even if the 100cm3 includes air spaces, the air can be compressed when substance b fills up the space, but in the end substance b and the marbles still take up 300cm3 of the space, and the remaining space is filled by the air. So, 700cm3!!!

[/quote]
Answer is 700cm3.... it's a relatively simple question but confusedly put across. Since it didn't mention is the 1 litre bottle capped, whether or not the last 100cm3 of the substance D is put in is not relevant at all.... the total volume of the bottle minus the substance B and marbles, the remaining space of 700cm3 is taken by the substance D.