2019 PSLE Discussions and Strategies (Children born in 2007)
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Nethan Nerella\" post_id=\"1938920\" time=\"1569902944\" user_id=\"178724:[quote=\"Nethan Nerella\" post_id=1938920 time=1569902944 user_id=178724]
No, i dont think so
Was there a potential--->kinetic + soumd[/quote] -
Paul was pushing a sofa. When Amy sat on it, he found it more difficult to push. Why is it so?
1)Gravitational force by Amy
2)Frictional force between sofa and floor
3)Frictional force between Paul and sofa
4) Potential to kinetic energy force or something
The qn is push, not lift.
More mass means more friction between floor and sofa. -
dottypooh\" post_id=\"1938909\" time=\"1569902362\" user_id=\"64091:
My DD also said the same. It's gravity. Cos only changing factor is the added weight. The rest are the same. Friction changes only when there is a change in surface.,ie, rougher or smoother.
if DD rmember correctly, its not friction. its due to gravity..quixation\" post_id=\"1938899\" time=\"1569901776\" user_id=\"480:
[quote=whitecarrotcake post_id=1938888 time=1569900796 user_id=114080]
Friction between sofa and floor
[/quot
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Yes, one option was potential to kinetic and another option was potential to kinetic to sound.
Normally it should be with sound energy but since Q18 requires conversion FROM THE MOMENT THE BALL HITS THE GROUND, it should NOT have sound energy because the ball is bouncing back up. -
When the ball is bouncing up…energy conversion is from kinetic to potential…not sure how the question was asked though…
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AnxiousabtPSLE\" post_id=\"1938927\" time=\"1569903392\" user_id=\"180550:
Can share the question? My DS's recall is incomplete.
Yes, one option was potential to kinetic and another option was potential to kinetic to sound.
Normally it should be with sound energy but since Q18 requires conversion FROM THE MOMENT THE BALL HITS THE GROUND, it should NOT have sound energy because the ball is bouncing back up. -
whitecarrotcake\" post_id=\"1938910\" time=\"1569902437\" user_id=\"114080:
Gravity is unless he's lifting the sofa. The qn is pushing sofa, so it's frictional force.[/quote]Same for dd.. friction btwn sofa and floor
if DD rmember correctly, its not friction. its due to gravity..quixation\" post_id=\"1938899\" time=\"1569901776\" user_id=\"480:
[quote=whitecarrotcake post_id=1938888 time=1569900796 user_id=114080]
Friction between sofa and floor -
Sofa question…should be friction…cause thats the only force opposing the push
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Iluvmygals\" post_id=\"1938929\" time=\"1569903613\" user_id=\"26453:
Dd says its on thr moment of ball bouce up..so kinetic + sound to potential for her.
When the ball is bouncing up....energy conversion is from kinetic to potential.....not sure how the question was asked though... -
thebusybee\" post_id=\"1938923\" time=\"1569903067\" user_id=\"4562:
Can he recall the question?
DS said he spotted a few tricky mcq qns which needed to read a few times to understand.
There's a qn abt young plant, after reading the graph carefully, his ans is - the seed starts to grow. Hope he got the right ans!
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