Q&A - PSLE Science

[anneshirleygilbert]

Winx5015:

Hi,


this question is found in my Pals are here - Science (energy) workbook.

Scientists are investigating a new type of wind power station, called the maglev wind turbine. By using repulsion between permanent magnets, the wind turbine is held in the air above the base of the machine. why does this save energy?

Thanks!

As the wind turbine is held in the air above the base of the machine, there is no friction, so there is no heat energy produced. Thus no energy is wasted.

Hope this helps.

[Winx5015]

Hi anneshirleygilbert,


Thanks for your help!

Good nite

[kitty2]

Deleted

[G Tan]

kitty2:

kitty2:

http://i41.tinypic.com/28a43zo.jpg\"> Please Help!!

Nobody knows the answer? :?

I cant see the question clearly!!!

[kitty2]

G Tan:

kitty2:

[quote=\"kitty2\"]http://i41.tinypic.com/28a43zo.jpg\"> Please Help!!

Nobody knows the answer? :?

I cant see the question clearly!!![/quote]Sorry i can't make it bigger,do you mind i email to you?
Thanks

[portal]

I have this qustion to ask.Substance x has to pass through various parts of a plantcell before reaching the nucleus.Which list below shows the correct order in which substance x has to pass through.

1]cellmembrane-cytoplasm-cellwall
2]cellwall-cellmembrane-cytoplasm
3]cellmembrane-cellwall-cytoplasm
4]cytoplasm-cellmembrane-cellwall
What is the ans.

[G Tan]

portal:

I have this qustion to ask.Substance x has to pass through various parts of a plantcell before reaching the nucleus.Which list below shows the correct order in which substance x has to pass through.

1]cellmembrane-cytoplasm-cellwall
2]cellwall-cellmembrane-cytoplasm
3]cellmembrane-cellwall-cytoplasm
4]cytoplasm-cellmembrane-cellwall
What is the ans.

answr is 2

[portal]

Thanks for the help

[portal]

I have this question to ask.

Which of the following statements about human reproduction is true?

A-To produce an offspring, two differnt sex cells are needed.
B-Sperm cells are made in large numbers in a special organ called the ovary.
C-A healty female normally produces an egg cell once in every three months.
D-The sperm cell carries half of the information needed for reproduction and the egg cell carries the other half.

1)A and B
2)B and C
3)C and D
4)A and D

[tianzhu]

portal:

I have this question to ask.

Which of the following statements about human reproduction is true?

A-To produce an offspring, two differnt sex cells are needed.
B-Sperm cells are made in large numbers in a special organ called the ovary.
C-A healty female normally produces an egg cell once in every three months.
D-The sperm cell carries half of the information needed for reproduction and the egg cell carries the other half.

1)A and B
2)B and C
3)C and D
4)A and D

Hi

In males, the testes produce sperm.

In females, from puberty, an egg is usually released from one of the ovaries every month.

So, this eliminates (1), (2) and (3).

The male produces reproductive cells called sperms.The female produces reproductive cells called eggs. The sperm cell carries half of the information needed for reproduction and the egg cell carries the other half.

The answer is (4).

Best wishes