2018 PSLE Discussions & Strategies (Born in 2006)

[puff]

lee_yl:

puff:

[quote=\"lee_yl\"]I am curious why that school teacher and tutor say it’s choice (4).


Btw, a sponge soaked with water is call a solid+liquid mixture. And can a solid ball be hollow, strictly speaking, no, else we are just playing with words

Thanks for the clarify a soaked sponge ball is not consider a solid. Steel solid ball could float on water due to
surface tension with precise calculation. So same material solid ball could sink or float depending on how it is place in the water. This sci qn have too many possibility how to say ans 4 is wrong.

Even if the solid metal ball can float on water due to surface tension and with precise calculations, say diameter must not exceed 2.6cm, then how can balls Y and Z made of the same material and identical, one end up floating and one sinking?

This question just wanted to test on the P3 material topic, and density is not within the PSLE syllabus.[/quote]Agree that ans 2 shouldn't be wrong if base on the p3 material topic tat is being taught. However ans 4 shouldn't be wrong either as there are too many possibility tat 2 same material can float or sink.

Floating due to surface tension can make material either float or sink .if u throw in the material with force it will sink ...if u place it gently enuff it will float ....mostly this experiment is done using needle but with very precise calculation it can be done on ball too.
Don't know if it is applicable to their sci qn but like i says too many possibility for this qn hence hard to says ans 4 is wrong.

What abt cotton ball ...1 cotton ball could have placed in the water first when it sink i place another cotton ball in hence the image of 1 floating cotton ball n 1 sink cotton ball.

[Sivak222]

Sctc:

I think the question did mention something like the pistil will fall off first followed by the stamen, meaning that they mature at different timing, that will prevent self pollination. I may be wrong.

As per my DS understanding, Male part and female part of flower bloomed at same time and live for 7 days after that either one fall off first, after 2 days next one fall. There is high chance to pollinate by insect with same flower.

[pungg]

Sivak222:

Sctc:

I think the question did mention something like the pistil will fall off first followed by the stamen, meaning that they mature at different timing, that will prevent self pollination. I may be wrong.

As per my DS understanding, Male part and female part of flower bloomed at same time and live for 7 days after that either one fall off first, after 2 days next one fall. There is high chance to pollinate by insect with same flower.

As per my DS also insect one flower( with same flower). Don't know which one is correct?

[Sivak222]

From Primary 3 material topics students learned only ability to float or sink. They give some examples for floating materials and some examples for sinking materials. Basic science teach only some type of materials float on water and some other types sink on water. Two solids sink one float means they want to know one type material like steel ball will sink and other type material like styrofoam ball will float. Not necessary to think density, surface tension. These are out of topics. Question will be within in the syllabus. I studied many primary science books before I teach my child, all books covered only material either float or sink. If we study general science topics we can consider other factors. Thanks.

[puff]

Sivak222:

Even if the solid metal ball can float on water due to surface tension and with precise calculations, say diameter must not exceed 2.6cm, then how can balls Y and Z made of the same material and identical, one end up floating and one sinking?


This question just wanted to test on the P3 material topic, and density is not within the PSLE syllabus.

Agree that ans 2 shouldn't be wrong if base on the p3 material topic tat is being taught. However ans 4 shouldn't be wrong either as there are too many possibility tat 2 same material can float or sink.

Floating due to surface tension can make material either float or sink .if u throw in the material with force it will sink ...if u place it gently enuff it will float ....mostly this experiment is done using needle but with very precise calculation it can be done on ball too.
Don't know if it is applicable to their sci qn but like i says too many possibility for this qn hence hard to says ans 4 is wrong.

What abt cotton ball ...1 cotton ball could have placed in the water first when it sink i place another cotton ball in hence the image of 1 floating cotton ball n 1 sink cotton ball.[/quote]

From Primary 3 material topics students learned only ability to float or sink. They give some examples for floating materials and some examples for sinking materials. Basic science teach only some type of materials float on water and some other types sink on water. Two solids sink one float means they want to know one type material like steel ball will sink and other type material like styrofoam ball will float. Not necessary to think density, surface tension. These are out of topics. Question will be within in the syllabus. I studied many primary science books before I teach my child, all books covered only material either float or sink. If we study general science topics we can consider other factors. Thanks.[/quote]

Did they learn under material eg plastic material or wood material there are different type of plastic/ wood material which may have diff outcome of the experiment. I think they learn gerneral classification of material hence diff wood or plastic to them is still under same material type.
Anyway i do hope that some teacher or tutor can shed some light on this qn.

[nicnac]

Wood, some float and some sink…

[Sivak222]

As per my DS understanding, Male part and female part of flower bloomed at same time and live for 7 days after that either one fall off first, after 2 days next one fall. There is high chance to pollinate by insect with same flower.[/quote]

As per my DS also insect one flower( with same flower). Don’t know which one is correct?[/quote]
If they give conditions like male and female parts matured at different timings, insect with two flower pollination will be correct.
But conditions said male and female part bloomed same time and stay live 7 days. But one part die 2 days earlier than other. So We no need to think about later part. It means 7 days Anther and stigma stay live for pollination. One (same)flower insect pollination will be correct answer.

[Sivak222]

nicnac:

Wood, some float and some sink..

They did not give any conditions. If they want to test same material will float or sink they will give condition like materials name , material wet or dry before put in water. Volume same or different. If they not give anything they only want to know type of materials either sink or float.

[lee_yl]

nicnac:

Wood, some float and some sink..

Although both are metals, when your hubby gives you a ring, either a gold ring or copper ring, would you think both are the same?

[pungg]

Sivak222:

As per my DS understanding, Male part and female part of flower bloomed at same time and live for 7 days after that either one fall off first, after 2 days next one fall. There is high chance to pollinate by insect with same flower.

As per my DS also insect one flower( with same flower). Don't know which one is correct?[/quote]
If they give conditions like male and female parts matured at different timings, insect with two flower pollination will be correct.
But conditions said male and female part bloomed same time and stay live 7 days. But one part die 2 days earlier than other. So We no need to think about later part. It means 7 days Anther and stigma stay live for pollination. One (same)flower insect pollination will be correct answer.[/quote]
Oh ok, so his answer might be correct. According to my son and his friend they are telling that they didn't gave much info about this question..