Q&A - P4 Science

[verykiasumummy]

atutor2001:

jedamum:

Atutor,

My boy answer part blue part red,my concern is will it be implied that there are some parts remain white?

Yes part of the flower will remain white because the xylems will not cover the entire surface area of the petals. I used to teach my children to write this way :

Part of the flower will have red strips while other part will have blue strips. The red strips and blue strips are caused by red solution and blue solution flowing in the xylems respectively.

by the way, i think the results may also be affected depending on the flower used in the experiment... having red or blue strips may apply for another type of flower, but not all...

my dd's experiment uses white rose and white carnation

[verykiasumummy]

jedamum:

Atutor,

My boy answer part blue part red,my concern is will it be implied that there are some parts remain white?

my dd's experiment did not have any white parts left over... i would say, all the petals changed color, some red and some blue (lighter tones compared to the solution)...

the teacher said the xylem tubes transport the water up to different petals that they are \"in charge of\", as in the petals depend on different xylem tubes for water... so it all depends if the flower has more petals connected to which tube to determine whether there will be more red or more blue petals in the end... however all petals should changed color...

as my dd used white carnation and white rose, the carnation was ok -- all changed color. for the white rose, there were 2 petals remaining as white but she realised the 2 petals were going to be yellow, which means no longer part of the flower... so as to say, the whole flower should change color..

[verykiasumummy]

smartmummy:

Hi all!

I have a doubt.How do u answer for (b).Usually the qn like \"what is the property of light....?\", I always see the answer is \"light travels in straight line\".My son asking why is not \" light can be reflected\"
http://i50.tinypic.com/2evw6px.jpg\">

hi smartmummy,

this is when adults like us start to think, \"light can be reflected\" also can ma... am i right?

i think in this case, if the reason is \"light can be reflected\", it means that even when the mirrors are placed at other positions different from the diagram, such as the side walls of the maze and not at the current positions, peter will not see ali at all... so the primary reason is \"light travels in straight line\" before \"light can be reflected\" by the mirrors.

at p5 level, as atutor had mentioned, both properties must be in the answer to gain the full 2 marks.

[verykiasumummy]

Bookwrappers:

Hi experts here. Would like to ask, in p4 sci. They learn light travels in straight line. Many experiments in guide books confirm this in various experiments.


However just curious, if light travels in straight lines, does it mean that when we light a torch in a dark room, the ray of light only shines in one direction so only the part that is shone will be seen. In that case, when we switch on the center ceiling light in a room, we should only see things right under the light and not at a corner?

u ask for experts here so if i answer u, i'm an expert?? LOL...
no la, i'm not an expert... just sharing my views...

light travels in a straight line, but it depends on the distance where it is shone as well.. if u shine a torch on the wall, say from 1m away, u see a bigger circumference of light shone on the wall, when u reduce the distance to, say 2cm, u see a smaller circumference on the wall.. this is probably also why our lights are placed on ceilings, so that a bigger circumference can be shone to light the whole room up.

the sun is very far away from earth, so it is able to shine the biggest circumference of light on earth with its rays..

i do rmb the path of light from a light source to be pointing outwards like a cone, and not just straight like a tube... donkey yrs ago since i last touched physics, cant rmb exactly... maybe other experts can help me explain that...

[atutor2001]

verykiasumummy:

my dd's sci experiment shows that the whole petal actually turn to the color of the water. it was an experiment conducted by her tuition centre...

Thanks for sharing your dd's experience at her tuition centre. Previously, I had tried converting the entire petal to the colour of my preference but never succeeded.

I have also found this video very similar to the question which is quite interesting

http://www.youtube.com/watch?v=AMvEVnAFCNA&feature=related

[verykiasumummy]

atutor2001:

verykiasumummy:

my dd's sci experiment shows that the whole petal actually turn to the color of the water. it was an experiment conducted by her tuition centre...

Thanks for sharing your dd's experience at her tuition centre. Previously, I had tried converting the entire petal to the colour of my preference but never succeeded.

I have also found this video very similar to the question which is quite interesting

http://www.youtube.com/watch?v=AMvEVnAFCNA&feature=related

maybe u chose wrong flower??

u can try using rose or carnation instead...

[smartmummy]

smartmummy:

Hi all!

I have a doubt.How do u answer for (b).Usually the qn like \"what is the property of light....?\", I always see the answer is \"light travels in straight line\".My son asking why is not \" light can be reflected\"

Jamesbond:

We can say mirror reflects the light which travels in st lines. That wud be apt for such questions.

atutor2001:

Hi smartmummy
You have actually asked the \"correct question\". This is an example of \"indirect way\" of questioning. Instead of reading the question as \"Explain why Peter can see Ali\", the student needs to be trained to rephrase the question as \"Explain using the properties of light, why Peter can see Ali.

Jamesbond's answer will suffice for P4 or if it is a (1) mark question at P5 or 6. However, if it is a (2) mark question at P5 or 6, it is safer to elaborate on how the said properties will help Peter to see Ali. So by some modification to Jamesbond's answer, we get

\"Peter can see Ali because light travels in a straight line and is reflected by Ali to the 2 mirrors and then to Peter's eyes.\"

:thankyou:

[smartmummy]

smartmummy:

Hi all!

I have a doubt.How do u answer for (b).Usually the qn like \"what is the property of light....?\", I always see the answer is \"light travels in straight line\".My son asking why is not \" light can be reflected\"

verykiasumummy:

hi smartmummy,

this is when adults like us start to think, \"light can be reflected\" also can ma... am i right?

i think in this case, if the reason is \"light can be reflected\", it means that even when the mirrors are placed at other positions different from the diagram, such as the side walls of the maze and not at the current positions, peter will not see ali at all... so the primary reason is \"light travels in straight line\" before \"light can be reflected\" by the mirrors.

at p5 level, as atutor had mentioned, both properties must be in the answer to gain the full 2 marks.

:thankyou:

[Jamesbond]

http://i47.tinypic.com/257h9a0.jpg\">


My DS has some doubts in answering the explanation regarding the observation for cup A. Can anybody help...

[jedamum]

Jamesbond:

http://i47.tinypic.com/257h9a0.jpg\">


My DS has some doubts in answering the explanation regarding the observation for cup A. Can anybody help...

my answer...

Both air and water occupy space but cannot occupy the same space. Although air can be compressed, the air in the cup still occupies space and cannot be fully displaced by the water in the basin when the cup was lowered into the basin.

parents, feel free to comment! :oops: my answer too long for 1 mark! :faint: