Q&A - P5 Science

[StudyRoom]

This is a tough one.


I think (3) is out, because the foil shouldn’t get hotter than the paper below.

If the foil was much bigger then I think the area under the foil won’t char since it can conduct heat away to other parts of the foil. But given the foil is small and wholly contained within the flame area, it is likely that the foil will be as hot as the paper below. So (1) isn’t very likely either. Unless the foil conducts heat away to the air above.

(2) and (4) looks wrong because the charred area is too large.

Of the four options I think (1) is the most likely.

But I think I’d try this over the kitchen stove to confirm…

[StudyRoom]

PSLEguru:

This is a tough one.


I think (3) is out, because the foil shouldn't get hotter than the paper below.

If the foil was much bigger then I think the area under the foil won't char since it can conduct heat away to other parts of the foil. But given the foil is small and wholly contained within the flame area, it is likely that the foil will be as hot as the paper below. So (1) isn't very likely either. Unless the foil conducts heat away to the air above.

(2) and (4) looks wrong because the charred area is too large.

Of the four options I think (1) is the most likely.

But I think I'd try this over the kitchen stove to confirm...

Just tried this experiment. The answer, if the foil is larger than the flame area, is (3). The foil conducts heat away from the hottest part of the paper and spreads it out over the area covered by the foil.

If the foil is smaller than the flame, then there is no difference. The paper chars according to the size of the flame. (1) is not the answer.

So in this case the best answer is (3).

[Jamesbond]

Thx to everybody…for your time and effort in helping me for the above question…

[Jamesbond]

Are water plants a good indicator of water pollution in a pond. Why?

[StudyRoom]

Jamesbond:

Are water plants a good indicator of water pollution in a pond. Why?

This question is quite subjective I think...
I would say, yes, because water plants live in the water and are susceptible to changes in the water quality.

But it also depends what is the definition of \"good indicator\".

It is also not generally the case that plants will die when there is water pollution. In fact, some factories dump chemicals high in nitrates. These cause an overgrowth of algae which can cause other organisms to die. http://www.wheatleyriver.ca/current-projects/wrig-pilot-nitrate-study/nitrates-and-their-effect-on-water-quality-a-quick-study/

[Nebbermind]

I think animals will die even faster than plants when there’s water pollution.

[StudyRoom]

Nebbermind:

I think animals will die even faster than plants when there's water pollution.

I was thinking that too. But the question asks if plants are a good indicator. Not if they are a better indicator than animals.

[Nebbermind]

PSLEguru:

Nebbermind:

I think animals will die even faster than plants when there's water pollution.

I was thinking that too. But the question asks if plants are a good indicator. Not if they are a better indicator than animals.

Which I agree is very subjective...once they mentioned 'good', one would wonder what is the reference pt.

[marstolive]

http://i43.tinypic.com/2ugeadg.jpg\"> can someone tell me if it's correct that there are 5 colour blind women as the answer stated.

[XXXX]

marstolive:

http://i43.tinypic.com/2ugeadg.jpg\"> can someone tell me if it's correct that there are 5 colour blind women as the answer stated.

I count 7 females daughters and grand-daughters but no solid black circles.