Q&A - PSLE Science

[verykiasumummy]

Tiramisu Coco:

Hi, need help for part (b) of this qtn. Thk u.


http://www.flickr.com/photos/82618212@N07/8005317651

hi Tiramisu Coco,

a temporary magnet will be able to attract paper clips once they have been magnetised but will soon lose its magnetism after some time. if the steel rods were able to attract paper clips after they have been stroked many times, they have become temperory magnet..

hope this helps..

[Tiramisu Coco]

verykiasumummy:

Tiramisu Coco:

Hi, need help for part (b) of this qtn. Thk u.


http://www.flickr.com/photos/82618212@N07/8005317651

hi Tiramisu Coco,

a temporary magnet will be able to attract paper clips once they have been magnetised but will soon lose its magnetism after some time. if the steel rods were able to attract paper clips after they have been stroked many times, they have become temperory magnet..

hope this helps..

Thks for the reply verykiasumummy. The qtn ask how to confirm if the two steel rods hv become temporary magnets. My query is, do we use a magnet to check or can we use the same poles of the two steel rods to chk if they repel each other? Very confused, hope someone can clarify. Thk u.

[verykiasumummy]

using another magnet to chk if it repels is not required to confirm if they have become temperary magnets, (only when u need to confirm an object is a magnet, as in permanent magnet) because temporary magnets are just for short term, so the repulsion may not be guaranteed.

[Michaelia0816]

I need help with a strange question!


Link:
http://t.co/OKxkv0ZZ

Thx!

[charsen]

Michaelia0816:

I need help with a strange question!


Link:
http://t.co/OKxkv0ZZ

Thx!

Hi
If i am not wrong ,the answer should be group Q.Because the characteristic in Group R consists of 3 sided organisms.Group S has organisms which are quadrilateral.
Group P has organism with no sides.Group Q has organisms which has two semi circle curvy lines.Organism A also has Two semicircle curvy lines if it is in the right position.
With this information,you should be able to do part b.
Cheers

[Winx5015]

Hi, can I know what is the answer for this question.


A glass of pure ice cubes are melting in the Sun. A thermometer is placed in the glass. As the ice melts, its temperature_______________ .

(1) is at 0 degree celsius
(2) is at 100 degree celsius
(3) is higher than the surrounding temperature
(4) is the same as the surrounding temperature

I feel that the answer should be (4) but the answer key is (1).

Thanks

[verykiasumummy]

Winx5015:

Hi, can I know what is the answer for this question.


A glass of pure ice cubes are melting in the Sun. A thermometer is placed in the glass. As the ice melts, its temperature_______________ .

(1) is at 0 degree celsius
(2) is at 100 degree celsius
(3) is higher than the surrounding temperature
(4) is the same as the surrounding temperature

I feel that the answer should be (4) but the answer key is (1).

Thanks

hello Winx5015,

ans is 1, because the temperature of melting ice, being still in ice state, will remain as 0 C.

[fightingmom]

Winx5015:

Hi, can I know what is the answer for this question.


A glass of pure ice cubes are melting in the Sun. A thermometer is placed in the glass. As the ice melts, its temperature_______________ .

(1) is at 0 degree celsius
(2) is at 100 degree celsius
(3) is higher than the surrounding temperature
(4) is the same as the surrounding temperature

I feel that the answer should be (4) but the answer key is (1).

Thanks

Hi Winx5015,

Answer is (1)

Concept:
Water can change from one state to another when it's temperature changes.
The temperature of water will increase or decrease until it reaches the point where the change takes place. It will then stay at that temperature until the change is completed

That is to say, the ice will stay at 0 degree celsius until all the ice has melted.

Thus, the same applies for boiling.

Hope it helps

[charsen]

Winx5015:

Hi, can I know what is the answer for this question.


A glass of pure ice cubes are melting in the Sun. A thermometer is placed in the glass. As the ice melts, its temperature_______________ .

(1) is at 0 degree celsius
(2) is at 100 degree celsius
(3) is higher than the surrounding temperature
(4) is the same as the surrounding temperature

I feel that the answer should be (4) but the answer key is (1).

Thanks

Hi
Answer is 1 as pure water melts at 0 degree celcius.
Cheers

[Winx5015]

verykiasumummy, fightingmom and charsen,


Thanks for your help and explanation. I understand now.