PSLE 2009 - Science

[mathsparks]

hi kohjl jr,

I'm so impressed with your answers. :congrats: You will surely get into the school of your choice. Go tell yr mumsy no worries!

[acelancer]

kohjl:

acelancer:

it's okay then do u noe the ans for the question about rod X and the magnet. They put a flame over rod x.u noe tht one?

Can you refresh my memory on what they asked for?

From kohjl Jr

what cause the ro to be attracted by th magnet?
a: (something to do with gravity)
b:the rod has lost its magnetism
(something about the flame and kinetic energy)

[acelancer]

acelancer:

kohjl:

[quote=\"acelancer\"]
it's okay then do u noe the ans for the question about rod X and the magnet. They put a flame over rod x.u noe tht one?

Can you refresh my memory on what they asked for?

From kohjl Jr

what cause the ro to be attracted by th magnet?
a: (something to do with gravity)
b:the rod has lost its magnetism
(something about the flame and kinetic energy)[/quote]kohjl Jr, what did u put? i put b&c but i'm not tht sure......

[kohjl]

acelancer:

kohjl:

[quote=\"acelancer\"]
it's okay then do u noe the ans for the question about rod X and the magnet. They put a flame over rod x.u noe tht one?

Can you refresh my memory on what they asked for?

From kohjl Jr

what cause the ro to be attracted by th magnet?
a: (something to do with gravity)
b:the rod has lost its magnetism
(something about the flame and kinetic energy)[/quote]Now I remember the question. I thought that the question was: What caused the rod to move?

Just to recap: there was a rod hanging from a string, and a magnet that was placed nearby caused the rod to be repelled, causing the rod to swing upwards slightly. A candle flame was placed directly under the rod. The rod started to move.

My answer: a & b
(It can't be c because the heat and light energy was not converted into kinetic energy)

Reason: Gravity was already acting on the rod from the start. When 2 equal forces are acting on each other in opposite directions, the resultant force is 0 as the magnetism cancels out the force of gravity. However, after heating, the rod will lose some of its magnetism. So the force of gravity is stronger than the magnetism and will cause it to move downwards.

From kohjl Jr

[kspslng]

kohjl:

The Question:

The farmer found that alot of caterpillars were eating his crops. The farmer sprayed alot of pesticides onto them. Which of the following is correct?

My answer:
Crops-increased
Fruits-increased

Reason: Even if the pesticides kill some of the plants, pesticides will kill most of the caterpillars. Since there are no more caterpillars feeding on the leaves, the number of crops will increase and therefore, the number of fruits will increase.

From: kohjl Jr

Depending on the exact wordings in the Q but assuming that wordings of the Q indiated here is correct, the Answer to this Q may lie in the key word \"The farmer sprayed \"alot of pesticides\" onto them.

[Aya]

What did everyone put for the first question? Some people in my class say that the ans is either 2. Stomach or 3. Small Intestines.


And how about the last question for Booklet B? That one was tough...

So, how many questions have everyone confirmed wrong for Booklet A? For me, already 2 questions Overall, I don't think the paper was easy at all... of course an exception for the science freaks out there.

[justsay]

kohjl:

Now I remember the question. I thought that the question was: What caused the rod to move?


Just to recap: there was a rod hanging from a string, and a magnet that was placed nearby caused the rod to be repelled, causing the rod to swing upwards slightly. A candle flame was placed directly under the rod. The rod started to move.

My answer: a & b
(It can't be c because the heat and light energy was not converted into kinetic energy)

Reason: Gravity was already acting on the rod from the start. When 2 equal forces are acting on each other in opposite directions, the resultant force is 0 as the magnetism cancels out the force of gravity. However, after heating, the rod will lose some of its magnetism. So the force of gravity is stronger than the magnetism and will cause it to move downwards.

From kohjl Jr

Hi Jr, same answer again. :lol:

[the ME]

Aya:

What did everyone put for the first question? Some people in my class say that the ans is either 2. Stomach or 3. Small Intestines.


And how about the last question for Booklet B? That one was tough...

So, how many questions have everyone confirmed wrong for Booklet A? For me, already 2 questions Overall, I don't think the paper was easy at all... of course an exception for the science freaks out there.

I wrote small intestine. I think it's wrong T.T The last question I guessed and checked. Was alright.

[kohjl]

the ME:

Aya:

What did everyone put for the first question? Some people in my class say that the ans is either 2. Stomach or 3. Small Intestines.


And how about the last question for Booklet B? That one was tough...

So, how many questions have everyone confirmed wrong for Booklet A? For me, already 2 questions Overall, I don't think the paper was easy at all... of course an exception for the science freaks out there.

I wrote small intestine. I think it's wrong T.T The last question I guessed and checked. Was alright.

The Question:
Which is the organ with the most digested food.

My answer:
Small intestine.

From: kohjl Jr

P/S - Going for dinner, so offline this evening.

[kohjl]

mathsparks:

hi kohjl jr,

I'm so impressed with your answers. :congrats: You will surely get into the school of your choice. Go tell yr mumsy no worries!

Hi mathsparks

FINALLY got my A/C back.... my son had hijacked it for most of this evening. He wanted to answer just one or two questions, but got carried away.

That's fine with me...helped to \"bump up\" my post ratings... :lol:
Thanks, mathsparks for yr well-wishes!

Regards.
kohjl
(The mother)