Q&A - PSLE Science

[SAHMwith2boys]

zinc6539:

SAHMwith2boys:

http://i49.tinypic.com/14ax1yc.jpg\">

Qn: State 2 advantages of using this pulley system.
Ans:
1. Less effort is needed to lift the load.
2. It changes the direction of the force.

Can someone explain what is the meaning of the 2nd point in the answer? Thanks.

I don't know what's in the syllabus now. But just to answer your question, point 2 means that one is now pulling in the direction of the gravitational force (downwards) instead of opposite (upwards). Hence leading to point 1.

Thanks for your answer. I went to MOE website to check, only found syllabus for yr 2008 science...anyway, I think it's good info for DS to know...

[pecalis]

Sun_2010:

SAHMwith2boys:

http://i49.tinypic.com/14ax1yc.jpg\">

Qn: State 2 advantages of using this pulley system.
Ans:
1. Less effort is needed to lift the load.
2. It changes the direction of the force.

Can someone explain what is the meaning of the 2nd point in the answer? Thanks.

Is this from an old paper?

I tot simple machines have been removed from the syllabus from 2010 psle batch?

Agree tt Simple Machines no longer in Sc syllabus. They will learn it in Sc Sch though...

[bestwishes]

Simple machine is not in the current pri sc syllabus. HOWEVER, as there are information or data provided in the qn (picture and table), the answers can be deduced easily. Hence, this qn is not considered out of syllabus qn.

[keinic]

Hi


Appreciate if someone could help with the following question extracted from NanHua 2012 CA1 paper. My DS's answer is 3 but the answer given is 2. Tks.

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[savoury sweet]

keinic:

Hi


Appreciate if someone could help with the following question extracted from NanHua 2012 CA1 paper. My DS's answer is 3 but the answer given is 2. Tks.

http://i47.tinypic.com/vnlgcg.jpg\">

what's the question number? image too small.

[keinic]

Hi savoury sweet


It's question 19. Tks.

http://i49.tinypic.com/wi9boy.jpg\">

[Jwoofamily]

Gravitational force is different from gravitational potential energy. GF is referring to gravity from earth. Therefore all have same GF. GPE is dependent on height of object. The higher the object from the ground, the higher the GPE.

[keinic]

Jwoofamily:

Gravitational force is different from potential gravitational energy. GF is referring to gravity from earth. Therefore all have same GF. PGEis dependent on height of object. The higher the object from the ground, the higher the PGE.

Thanks for the detailed explanation.

[Mary Joy]

pls help with these food chains…


grass----->?------->?--------->Man

seed------->sparrow--------->?------------>?___

[mother777]

Grass—>grasshopper—>chicken—>man