Q&A - P5 Science

[tianzhu]

whywhy:

im so sorry i hav forgotten to mention is SCIENCE paper booklet A.

Hi

I think students learned in P4 that the rate of evaporation is determined by how fast a liquid evaporates.

Evaporation rate depends on four factors.

Temperature
Presence of wind
Exposed area
Humidity of surrounding air.

In this MCQ, students are expected to compare the rate of evaporation based on the exposed area of the t shirts.

The greater the exposed area of the t shirts, the faster is the evaporation rate.

Hence (2) is correct.

http://www.orlesson.org/orp/11Sc/2011-P5-Science-SA1-Nanyang.pdf

Best wishes

[mother777]

SAHMwith2boys:

http://i44.tinypic.com/8wh4ya.jpg\">


DS answer that the container C would contain the most amount of air because it allows the most amount of water to replace the space taken up by the air.

Answer provided states that it should be container B instead because the trapped air in the soil in container B takes up the most space thus leaving the most amount of water above the soil. We cannot understand the answer given because when pouring the water in, the air would have escaped and water would have taken up the space originally taken up by the air, so the ans given doesn't seem logical. Appreciate if there's any advise from others on this qn.

Thanks.

Hi,
Your son is correct.
Pls refer to the explanation in the link below. it is nearly the same example as the question you are seeking answer for.

http://www.education.com/science-fair/article/earth-science_airy/

Hope this helps you out

[atutor2001]

SAHMwith2boys:

SAHMwith2boys:

http://i44.tinypic.com/8wh4ya.jpg\">


DS answer that the container C would contain the most amount of air because it allows the most amount of water to replace the space taken up by the air.

Answer provided states that it should be container B instead because the trapped air in the soil in container B takes up the most space thus leaving the most amount of water above the soil. We cannot understand the answer given because when pouring the water in, the air would have escaped and water would have taken up the space originally taken up by the air, so the ans given doesn't seem logical. Appreciate if there's any advise from others on this qn.

Thanks.

I find that both ans B and C are possible depending on the explanation given. However, this is very confusing to DS who don't know which is the right ans he should provide in exam scenario...sigh...any other help?

The question states that :

\"Brian wanted to find out the amount of air retained by different types of soil.\"

However, because water was used to find the amount of air retained, it created the confusion and the misinterpretation that the aim was :

\"Brian wanted to find out the amount of air retained by different types of soil after water was poured into it.\"

If we read the question carefully, the words in red were not Brian's intention. Therefore, C is the answer.

Incidentally, the volume of water above the soil cannot indicate the amount of air retained after water is poured into the soil because this volume depends on both the original amount of air trapped in the soil and the amount of air retained. This volume will be the biggest if there is zero air space in the soil although actually there is no air retained.

[SAHMwith2boys]

Thanks to all for help. Anyway, have explained and asked DS to maintain his answer and hopefully I’m not leading him the wrong way. His sci teacher in sch dun actually teach…sigh…thus the need for us to look for ans ourselves.

[SAHMwith2boys]

http://i48.tinypic.com/2a5emwj.jpg\">


Another qn looking for help. Ans given was (2) Water Lily. DS and me have totally no idea why.... :?:

[whywhy]

Thank u, Tianzhu.

[tianzhu]

whywhy:

Thank u, Tianzhu.

Hi

Good Morning.

You're welcome.

Best wishes

[tianzhu]

SAHMwith2boys:

http://i48.tinypic.com/2a5emwj.jpg\">


Another qn looking for help. Ans given was (2) Water Lily. DS and me have totally no idea why.... :?:

Hi

I am more inclined to go for (3).

A sudden increase in the population of water hyacinth blocks sunlight and prevent the hydrilla from carrying out photosynthesis to survive.

Best wishes

[SAHMwith2boys]

tianzhu:

SAHMwith2boys:

http://i48.tinypic.com/2a5emwj.jpg\">


Another qn looking for help. Ans given was (2) Water Lily. DS and me have totally no idea why.... :?:

Hi

I am more inclined to go for (3).

A sudden increase in the population of water hyacinth blocks sunlight and prevent the hydrilla from carrying out photosynthesis to survive.

Best wishes

DS would be really glad to see ur reply, he had the same theory as urs.... ...really wonders how r we gg to survive for P6 science...

[Michaelia0816]

SAHMwith2boys:

tianzhu:

[quote=\"SAHMwith2boys\"]http://i48.tinypic.com/2a5emwj.jpg\">


Another qn looking for help. Ans given was (2) Water Lily. DS and me have totally no idea why.... :?:

Hi

I am more inclined to go for (3).

A sudden increase in the population of water hyacinth blocks sunlight and prevent the hydrilla from carrying out photosynthesis to survive.

Best wishes

DS would be really glad to see ur reply, he had the same theory as urs.... ...really wonders how r we gg to survive for P6 science...[/quote]Hey! This is in my textbk, and in my textbk got the similar question but My answer is also similar to Tianzhu but more clearer and specific, you may consider looking in Psle Revision Guide!