Q&A - PSLE Science

[chrisu]

Thanks atutor2001 and nebbermind. Yes the answer is (3). Since this is the MCQ portion, guess the students need to answer within 2 minutes is quite tough.

[Sun_2010]

chrisu:

Thanks atutor2001 and nebbermind. Yes the answer is (3). Since this is the MCQ portion, guess the students need to answer within 2 minutes is quite tough.

Agree with atutor2001 that it is reasonable

Yes the question is tough but within the grasp of a P6 child. Afterall it is about applying our knowledge to real life scenarios, logical thinking. Some such questions are necessary to separate out the levels. As long as the paper is not filled with such questions I feel it is fair.


PS- I think my daughter had a similar Q last year in SA1 or Prelim ....

[Verysuperkiasu]

:oops: Came across a question from Pei Chun prelim 2011 section B Q38


Expt is about 3 similar springs suspended by materials A, B, C (all 50g). 2 pieces of object X are placed below A and C. Picture shows A suspended very high up furthest from X below it. while C is very closed to X below it. B is suspended in the middle.

There is one part that asks what can X be. - Answer should be a magnet as both A and X repelled each other.

But next question ask 'what material is block A made up of- explain.
Both A and X have to be magnets (they repel) but can the material be called 'lodestone' or 'iron'?

(sorry I don't have a scanner so hv to describe the picture) :oops:
hope one of u can help??

[atutor2001]

The questions is \"what material is block A made up of?\" The word \"is\" means \"definitive\" i.e. must be correct.


Therefore, putting either lodestone or iron will be wrong because we can't be sure/definite that it is iron or lodestone.

The correct answer is \"magnetic material\" because, all and only, magnetic material can be made into a magnet.

[Verysuperkiasu]

atutor2001:

The questions is \"what material is block A made up of?\" The word \"is\" means \"definitive\" i.e. must be correct.


Therefore, putting either lodestone or iron will be wrong because we can't be sure/definite that it is iron or lodestone.

The correct answer is \"magnetic material\" because, all and only, magnetic material can be made into a magnet.

Oh, I see. You mean if the question asks 'what possible material can A be made up of' then I am right to put lodestone or iron?

[Verysuperkiasu]

atutor2001:

The questions is \"what material is block A made up of?\" The word \"is\" means \"definitive\" i.e. must be correct.


Therefore, putting either lodestone or iron will be wrong because we can't be sure/definite that it is iron or lodestone.

The correct answer is \"magnetic material\" because, all and only, magnetic material can be made into a magnet.

Oh, I see. You mean if the question asks 'what possible material can A be made up of' then I am right to put lodestone or iron?

[stary]

Hi all,


Need explanation for the following...

RGPS/SA1/P6/2010
Question 30:

http://www.flickr.com/photos/64113082@N03/6143567445/in/photostream
http://www.flickr.com/photos/64113082@N03/6143567451/in/photostream

My ans:3
Ans key:2

Many thanks!

[atutor2001]

Verysuperkiasu:

atutor2001:

The questions is \"what material is block A made up of?\" The word \"is\" means \"definitive\" i.e. must be correct.


Therefore, putting either lodestone or iron will be wrong because we can't be sure/definite that it is iron or lodestone.

The correct answer is \"magnetic material\" because, all and only, magnetic material can be made into a magnet.

Oh, I see. You mean if the question asks 'what possible material can A be made up of' then I am right to put lodestone or iron?

Yes, other words that allow the naming of actual materials are \"suggest\", \"likely\"... sorry can't remember leow

[ms_lim]

Please help on this question :


http://i56.tinypic.com/2d1u350.jpg\">

Ans key is (1) but my dd explains that D protects the spinal cord so her ans is (3). Is spinal cord a vital organ?

[atutor2001]

stary:

Hi all,


Need explanation for the following...

RGPS/SA1/P6/2010
Question 30:

http://www.flickr.com/photos/64113082@N03/6143567445/in/photostream
http://www.flickr.com/photos/64113082@N03/6143567451/in/photostream

My ans:3
Ans key:2

Many thanks!

Gravitational force is constant as long as the object is near the Earth surface. So answer is 2.

Gravitational force depends on the distance between the centre of the Earth to the ball. The greater the distance, the smaller will be the gravitational force.

However, the radius of the Earth (6370 km) is so very much longer than the vertical distance of the ball from the ground (only a few m). Therefore, the change in distance, caused by the movement of the ball, will be negligible i.e. changing a few metres to 6370 km has no significant effect. As such the gravitational force experienced by any object near the Earth surface is taken to be constant.

On the other hand, a plane flying many km up in the sky will experience lower gravitational force because the change is more significant.