Please help.


MSG SA1


Q26) When a child suffers from high fever, there is a practice to place a wet towel around the child's head and neck. What do you think is the possible reason for doing that?

(1) The wet towel provides coldness to the body.
(2) The wet towel is a poor conductor of heat to prevent heat from entering the body.
(3) The wet towel is a good conductor of heat to conduct heat away from the body.
(4) The wet towel allows evaporation to happen around the body.

Worksheet answer is 4).

My answer is (1.

Which is correct?


Q29) Please refer to the picture.

Worksheet answer is (2).

My answer is (4).

Which is correct?



Q33c) Please refer to the question and picture attached.

My answer is sunlight and water.

Will it be acceptable?

TIA.

Q26) When a child suffers from high fever, there is a practice to place a wet towel around the child's head and neck. What do you think is the possible reason for doing that?

(1) The wet towel provides coldness to the body.
(2) The wet towel is a poor conductor of heat to prevent heat from entering the body.
(3) The wet towel is a good conductor of heat to conduct heat away from the body.
(4) The wet towel allows evaporation to happen around the body.

Worksheet answer is 4).

My answer is (1.

Which is correct?

Generally we tend to think it adds cold to the body but I think 4 would be correct.

1) Adding coldness to the body is not what we need. Adding more cold would make the body work harder increasing the fever.
2) Water is a good conductor of heat. (Compared to wat a dry towel?)
3) Water is a good conductor of heat and should help bring the temperature down. I think this answer is correct. I could also use other materials to do this too or place the body in luke warm water.
4) I think is more correct because adding the small amounts of water around the body will help to cause evaporation which is how the body cools itself.

So I think 4, but I also think 3 is correct. but maybe not as correct

Q26 I would have thought the answer was 3.

Q29. I agree with that it should be 4. I printed it out and measured using the rules for the angles of reflection. I wonder though, I doubt the kids will be expected to take a protractor into science, if the answer is trying to show the intention of the experiment. Based on the position of the mirrors one would think 2 is correct. Technically I think 4 is correct.

Q33c) My answer is water and oxygen. Normally seeds do not need light to germinate. In fact some seeds only germinate in the dark. Once the new leaves grow, the young plant will need sunlight for photosynthesis.

26. The ans should 4 as when evaporation occurs, it produces a cooling effect, just like sweating

33c) I personally think that sunlight is wrong as the seed has seed leaves for it to feed on. Hence, it should just be Warmth/Oxygen/Water.

Good Answers Tze Hao.

In Science, we usually describe the movement of heat energy as opposed to coldness.
Coldness is just the absence of heat.

On the other hand, in the handling of high fevers, something a cold sponge bath is given. Although "coldness" is not a proper scientific concept. Providing coldness is not entirely wrong, in the sense that cold sponges or cold towels absorb sensible heat from the body as well as latent heat which evaporates the water.

A BIG reason why we put a wet towel on the head and neck or sometimes, give a person with a high fever, a wet body sponge, is that when the moisture evaporates from our body it draws heat from our body and uses this heat as latent heat of evaporation.

The answer: "because it is a good conductor", is not fully sensible. Why would we say a wet towel is a good conductor of heat? I would say steel, copper or metals are good conductor of heat, not wet towels.

I would like to say Ans(4) is the most appropriate answer for question 6. However, it is not very well framed. Since, we are placing the wet towels on the head, I would tend to say

"The wet towel allows increases evaporation to happen around the bodyat the head and neck area"

"Allows" is a poor choice of words, because with or without a wet towel on the head and neck evaporation is allowed to ocur.

We are placing the wet towel on the head and neck what has that got to do with evaporation at the rest of the body.

I would like to add, that cooling the head and neck area is critical.

As the brain is very sensitive to high temperatures and brain damage can occur if the temperature at the head/neck area is too high.

P56 wrote:
MSG SA1

Q33c) Please refer to the question and picture attached.

My answer is sunlight and water.

Will it be acceptable?

TIA.


Your answer is acceptable since the question asks about the conditions required for the young seedlings to grow and the picture states that 'After a week'.


So we are talking about Day 8 onwards, as the young seedlings already have their own leaves, they will need sunlight to make food.

Hi,

Yup, Tang has a good point there that the discussion for part (c) is for week old seedlings and not germination of seeds.

On a further note; hope some science guru on botany can clarify some further questions to with respect to question 33a.

Is a seedling a young plant that has already germinated from a seed?
If so, since the setter has used the word "seedling" instead of "seed", wouldn't that take "germination" out as a possible answer for 33(a). What would a good answer be? "Growth" ?

Thanks.