Q&A - PSLE Science

[atutor2001]

anneshirleygilbert:

Can these two terms \"chemical energy\" and \"chemical potential energy\" be used interchangeably in answering Open-Ended questions in PSLE? Do they mean the same thing? I see these terms in different answer sheets. Please help.

It is wrong to use \"Chemical energy\" as a replacement for \"Chemical Potential Energy\" \"Chemical energy\" means a totally different thing and is not the potential energy that Pr sch is learning. It should be covered in either Sec or JC, can't remember. Use only \"chemical potential energy\" Ignore those answer sheets.

[elkniwt]

Dear tianzhu and atutor2001,


Thank you very much for your help!!!

[anneshirleygilbert]

Thanks, elkniwt and atutor2001, for the clarification. Appreciate your help very much.

[tinasen]

Can anyone help to explain the correct reasoning for this Qn.

The diagram shows an undulating slope. A ball was released from point of the slope. At which point P, Q, R or S , of the slope will the ball have the most gravitational potential energy?
(1) Point P (2) Point Q (3)Point R (4) Point S
The correct answet given in answer key is option (1) where as my DS chose wrongly as (3). http://i42.tinypic.com/35ata8g.jpg\">

[Sun_2010]

tinasen:

Can anyone help to explain the correct reasoning for this Qn.

The diagram shows an undulating slope. A ball was released from point of the slope. At which point P, Q, R or S , of the slope will the ball have the most gravitational potential energy?
(1) Point P (2) Point Q (3)Point R (4) Point S
The correct answet given in answer key is option (1) where as my DS chose wrongly as (3). http://i42.tinypic.com/35ata8g.jpg\">

The ball will not have the energy to reach PointR since R is at a higher position than P . As such between P and Q, the PE is higher at P

[G Tan]

elkniwt:

anneshirleygilbert:

Can these two terms \"chemical energy\" and \"chemical potential energy\" be used interchangeably in answering Open-Ended questions in PSLE? Do they mean the same thing? I see these terms in different answer sheets. Please help.

Hi anneshirleygilbert,

According to my dd, their teacher told them to use the term \"chemical potential energy\" instead of \"chemical energy\".

Regards.

I agree alos. Use CPE is the safest

[G Tan]

bestwishes:

Selfan4ever♥23:

[quote=\"Koky462\"]I have an question on the method of reproduction from my son's exercise.


x - Man, Frog, Polar bear\t\t
y - Yeast, Amoeba, Paramecium
\t
a)What is the main difference between the two methods of reproduction for X & Y?
b)Name the reproduction method under the sub-heading X.

b) External

a) X: Sexual reproduction (involves 2 parents of opposite sexes; involves fertilisation)
Y: Asexual reproduction (involves a single parent; not involve fertilisation)

Frogs in X -- external fertilisation
Mammals in X -- internal fertilisation
Yeast in Y -- budding (a kind of cell division)
Amoeba & Paramecium in Y -- binary fission (a kind of cell division)[/quote]External and internal fertilisation is nt in syllabus anymore

[tinasen]

Thank you!

Sun_2010:

tinasen:

Can anyone help to explain the correct reasoning for this Qn.
The diagram shows an undulating slope. A ball was released from point of the slope. At which point P, Q, R or S , of the slope will the ball have the most gravitational potential energy?
(1) Point P (2) Point Q (3)Point R (4) Point S
The correct answet given in answer key is option (1) where as my DS chose wrongly as (3). http://i42.tinypic.com/35ata8g.jpg\">

The ball will not have the energy to reach PointR since R is at a higher position than P . As such between P and Q, the PE is higher at P

[anneshirleygilbert]

Hello,


I’m having trouble with terminology again! In the topic on Energy, do the terms, "transferred to", "converted into" and "changed to" all mean the same thing? The PSLE guide book uses all 3 terms… will a student be penalized for a ‘wrong choice’ of term, especially in the Open-Ended questions? Please help.

[jesschan]

Hi! Has anyone tried Aitong’s 2011 CA1 MCQs? The answer sheet that I have seems to be full of mistakes. What are your answers to Questions 1,4, 5, 11 & 25?