Q&A - P4 Science

[verykiasumummy]

Nebbermind:

Container has fixed shape n volume. Inflatable objects do no have fixed shape or vol UNTIL they reach they final capacity.

yup u r right... much as i sometimes disagree with some of the answers given, i learnt to forgo about the \"think too much\" logic so as to accept those answers in order to teach my dc... i still hv 2 more to go for psle, so i have to stand by firm with the concepts to teach them...

using a container that has fixed shape and volume, the concept is quite clear cut. i would only say that the setter of the question wants students to apply same logic for the case of the deflated ball.

[Nebbermind]

That’s why I usually donch trust those assessment books as I feel that their questions are not thought thru thoroughly and they even recycled questionable questions!!

[verykiasumummy]

Nebbermind:

That's why I usually donch trust those assessment books as I feel that their questions are not thought thru thoroughly and they even recycled questionable questions!!

they dun proof read into the questions that much... that's why the same problem persists...

i do understand that for a deflated ball, since capacity is 400cm3, when only 350cm3 is inserted, the ball may not be fully round yet, and as air does not have the pushing force to round the ball, the volume of air inside should depend on how inflated or deflated the ball is at that moment..

i learn to forgo those anyway... no point wasting time to think too much to outsmart the teacher or setter. might as well spend more time instilling correct concepts in my dc...

[sleepyqueen]

tayobus:

http://i49.tinypic.com/2aont0.jpg\">


Dear All,
My child is doing the past year paper and when come to the above question, he said not his level topic and he found out from the PSLE Science guide book it is upper block topic. Can anyone advise does your P4 child learnt the above? How do your child answer the above? By the way, this is taken from Nan Hua Pri SA2 2011 paper.

:thankyou:

Hi all,
I think this question not necessary be the upper level one as the kid are taught in p3 that flower will change colour if dip in coloured water. Now the stem is cut into 2 and soaked in different coloured solution. P3 the kids are also taught that roots take in water and the stem transport it to the other parts of the leaves.

[sleepyqueen]

milomilo:

Help needed:


Gopal pumped air into 2 footballs. The footballs when fully inflated each have a capacity of 400cm3. For football A, he pumped 350cm3 into it and for football B he pumped 405cm3. Which of statement is correct?

(1) Ball A is heavier than Ball B
(2) Ball B has 405cm3 of air inside it
(3) Both Ball A and B has 400cm3 of air inside it
(4) Ball A and Ball B are of the same mass after air was pumped in.

Note: Answer (1) and (4) are obvious wrong.

Thanks!

this question my answer is 3 as the volume 400cm3 is fixed cannot change.

[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?

[smartmummy]

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?

My thinking as follows,Diameter of torchlight much smaller than ceiling light. Sun's diameter sooooo big that's why we all can see at day time.

[Nebbermind]

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?

Firstly, the light source does not produce a single beam, and also a certain amt of light will lo be reflected by the various surfaces in the room.

If u gave a single beam such a one from a laser pointer, u can't see much with it.

[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\">

[Jamesbond]

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\">

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