2019 PSLE Discussions and Strategies (Children born in 2007)
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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
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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! -
LeeTaiTai\" post_id=\"1938934\" time=\"1569904000\" user_id=\"17608:
My dd ans is the same as yr gal
Dd says its on thr moment of ball bouce up..so kinetic + sound to potential for her.Iluvmygals\" post_id=\"1938929\" time=\"1569903613\" user_id=\"26453:
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:
DS said his answer is KE to SE + (elastic) PE...his reasoning is all GPE would have been converted to KE when it hit the floor, which is then converted to (elastic) PE since it’s a rubber ball...He couldn’t recall other options with KE to PE + whatever
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.
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