PSLE 2009 - Science
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kohjl:
The Question is:
I think soMummyJamie:
[quote=\"caroline3sg\"]mummyjamie & sahimi
my girl said biceps/triceps (is labelled as one letter) & the other one is the fulcrum - the elbow. So it is P & R?
The diagram shows a man exercising by raising a dumbell. Which of the following are needed for this action?
a) The biceps and the triceps
b) The elbow
c) The lower arm (bone)
My answer: All of the above.
Reason: The lower and upper arms are like levers. The elbow is the fulcrum, the muscles apply the effort and the lower arm is part of the lever. So, you need all three!
From: kohjl Jr :D[/quote] :!: Not only A*, I'm not surprised if you get full marks. Thanks for sharing !
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Yes fish bone and crab shell are bio degradable
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acelancer:
yup[/quote]The Question:
same answer... Hope it's correct...hot_chocolate:
[quote=\"justsay\"]
veg increase, fruit trees decreased ?
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
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kohjl:
wait, i think i changed it to ur ans. ah! i kei kiang again!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 -
Hello:
I put water and oxygen.What are the need(s) for a bread to turn mouldy?
(A)Oxygen
(B)Can't remember
(C)Water.
Its something like that.
From: kohjl Jr
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acelancer:
I put B and anther.
yup! i put tht too! at first i was stump by it.....Vaizard:
Hello, I am a candidate taking the PSLE.
What is the answer for the question about the flower wrapped with plastic bag? Is the answer B and anther? :shock:
From kohjl Jr
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atutor2001:
The Question:
This is amazing! Are they kidding by setting such question? The key words is \"longer distance\".caroline3sg:
kohjl
thank you.
There is one question about which can travel a longer%20distancein a desert, lizard & snake.
My girl's ans sounds logical but I worry the way she phrased it.
2 reasons (my own words, but her meaning:)
1) snake has no legs, there is frictional force when gliding on the (hot - not sure this word was mentioned in her ans or not) sand.
Personally, I think the longer body also plays a part on its contact on larger surface of the sand.
2) lizard uses front legs to run, hind legs to push it faster. Faster must be linked to longer distance, but don't know / didn't state.
Are they testing adaptation for heat? I remember snake moves under the sand in the desert to shield from the hot sun. If that is the case, then it should be snake because lizard cannot move under the sand.
Hi Kohjl Jr, what is your take?
There are 2 diagrams. The first shows a snake slithering (but the question put it as crawling) and the other shows a lizard running.
NOTE: The question already stated that the lizard moves faster than the snake (not travel a longer distance).
Then the question asked: Give 2 reasons.
My answer:
Reason 1:As the whole snake's body is in contact with the sand while the lizard only has its feet on the sand, there will be more friction between the snake and the sand than the lizard and the sand. So the lizard will move faster.
Reason 2: As the snake moves in a zig-zag while the lizard moves in a straight line, the snake has to move a longer distance than the lizard.
But I am not sure whether my asnwer is correct. Can anyone confirm? Thanks.
From: kohjl Jr
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kohjl:
The Question:
yupacelancer:
[quote=\"hot_chocolate\"]
same answer... Hope it's correct...
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 :D[/quote]As you have mentioned it killed most of the caterpillars but not all. The remaining caterpillars will then multiply and feed of the fruits. So shouldnt it be crop increased and fruit decreased ? -
Hi,
I am a candidate who have just taken the PSLE Science exam. Just wanted to know, what is the correct answer for this question:
Two bulbs are arranged in series. When one bulb is added to the circuit in parallel arrangement, what would happen to the brightness of the first bulb which was arranged in series?
1) It would not light up.
2) It would become brighter.
3) It would become dimmer.
4) It's brightness would remain the same.
Thank you -
kohjl:
The Question:
This is amazing! Are they kidding by setting such question? The key words is \"longer distance\".atutor2001:
[quote=\"caroline3sg\"]kohjl
thank you.
There is one question about which can travel a longer%20distancein a desert, lizard & snake.
My girl's ans sounds logical but I worry the way she phrased it.
2 reasons (my own words, but her meaning:)
1) snake has no legs, there is frictional force when gliding on the (hot - not sure this word was mentioned in her ans or not) sand.
Personally, I think the longer body also plays a part on its contact on larger surface of the sand.
2) lizard uses front legs to run, hind legs to push it faster. Faster must be linked to longer distance, but don't know / didn't state.
Are they testing adaptation for heat? I remember snake moves under the sand in the desert to shield from the hot sun. If that is the case, then it should be snake because lizard cannot move under the sand.
Hi Kohjl Jr, what is your take?
There are 2 diagrams. The first shows a snake slithering (but the question put it as crawling) and the other shows a lizard running.
NOTE: The question already stated that the lizard moves faster than the snake (not travel a longer distance).
Then the question asked: Give 2 reasons.
My answer:
Reason 1:As the whole snake's body is in contact with the sand while the lizard only has its feet on the sand, there will be more friction between the snake and the sand than the lizard and the sand. So the lizard will move faster.
Reason 2: As the snake moves in a zig-zag while the lizard moves in a straight line, the snake has to move a longer distance than the lizard.
But I am not sure whether my asnwer is correct. Can anyone confirm? Thanks.
From: kohjl Jr :D[/quote]my first reason was sort of same as urs but the 2nd one is different. urs make great sense but i'm not tht sure. sry. but i read about some animal able to travel in a zig zag manner. but for 2nd reason i wrote tht as the lizard as less contact with the hot sand then the snake, it will be able to travel longer as it will experience less heat while the snake has its whole body having contact with the sand and has more heat so it will not travel as far as the lizard. is my reasoning ok?
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