Q&A - PSLE Science

[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.

[atutor2001]

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?

I agree with your dd answer. Spinal cord is an organ as it is made up of tissues (definition of an organ) and it is also a vital one.

[Verysuperkiasu]

atutor2001:

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

Ok, got it. Thanks, atutor!

[Alchemist]

Hi


1) ACS Prelim Science Booklet A - No 17. Can someone pls tell me what is the answer. The given answer is 2. However, my son's teacher told the class that flowers have chloroplasts as well. So he claims the only part without chloroplasts in the root. http://i55.tinypic.com/orsfpv.png\">

[Alchemist]

This is my second query for the St Nic 2011, Prelim Q 8. Given answer is 4.

[Alchemist]

trying repost picture as it was too small http://i56.tinypic.com/2yn2uqc.png\">

[Nebbermind]

(1) Just learnt that spinal cord is an organ. Thanks to this forum!! But is it taught as such in schools?


(2) Believe that it’s taught that flower do not have chloroplast.

(3) Mangrove fruits is also dispersed by water so shd be (4)