2019 PSLE Discussions and Strategies (Children born in 2007)

[whitecarrotcake]

quixation\" post_id=\"1938899\" time=\"1569901776\" user_id=\"480:

whitecarrotcake\" post_id=\"1938888\" time=\"1569900796\" user_id=\"114080:

[quote=shutter post_id=1938864 time=1569898013 user_id=5938]anyone knows the ans for MCQ sofa qn?

Friction between sofa and floor

if DD rmember correctly, its not friction. its due to gravity..[/quote]Gravity is unless he's lifting the sofa. The qn is pushing sofa, so it's frictional force.

[phtthp]

ihatecompo\" post_id=\"1938896\" time=\"1569901084\" user_id=\"181387:

For me I only found the spring question tricky

any unusual question, came out ?

[dottypooh]

whitecarrotcake\" post_id=\"1938910\" time=\"1569902437\" user_id=\"114080:

quixation\" post_id=\"1938899\" time=\"1569901776\" user_id=\"480:

[quote=whitecarrotcake post_id=1938888 time=1569900796 user_id=114080]

Friction between sofa and floor

if DD rmember correctly, its not friction. its due to gravity..

Gravity is unless he's lifting the sofa. The qn is pushing sofa, so it's frictional force.[/quote]Actually.. what's the exact qn? Hehehe .. my DD nvr tell me in detail cos too eager to go out with friends to celebrate

[Nethan Nerella]

AnxiousabtPSLE\" post_id=\"1938905\" time=\"1569902232\" user_id=\"180550:

But question 18 requires the energy conversion THE MOMENT it hits the ground....so CANNOT HAVE SOUND ENERGY because it is when the ball is bouncing back up .

Exactly!

[whitecarrotcake]

dottypooh\" post_id=\"1938909\" time=\"1569902362\" user_id=\"64091:

quixation\" post_id=\"1938899\" time=\"1569901776\" user_id=\"480:

[quote=whitecarrotcake post_id=1938888 time=1569900796 user_id=114080]

Friction between sofa and floor

if DD rmember correctly, its not friction. its due to gravity..

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.[/quote]Greater mass means more friction between floor and sofa. I think this is one of the trickier qns.

[Nethan Nerella]

panickymum\" post_id=\"1938902\" time=\"1569901985\" user_id=\"64662:

helpthismom\" post_id=\"1938898\" time=\"1569901397\" user_id=\"149507:

Anyone knows the answer for Q18 the rubber ball question about the energy conversion?

Potential to kinetic and sound energy

Was that option 1? What option was it?

[Nethan Nerella]

panickymum\" post_id=\"1938902\" time=\"1569901985\" user_id=\"64662:

helpthismom\" post_id=\"1938898\" time=\"1569901397\" user_id=\"149507:

Anyone knows the answer for Q18 the rubber ball question about the energy conversion?

Potential to kinetic and sound energy

Was that option 1? What option was it?

[Nethan Nerella]

panickymum\" post_id=\"1938902\" time=\"1569901985\" user_id=\"64662:

helpthismom\" post_id=\"1938898\" time=\"1569901397\" user_id=\"149507:

Anyone knows the answer for Q18 the rubber ball question about the energy conversion?

Potential to kinetic and sound energy

Was that option 1? What option was it?

[N.020724rut0]

AnxiousabtPSLE\" post_id=\"1938907\" time=\"1569902316\" user_id=\"180550:

So Q18 should be just potential to kinetic

I thought the moment any ball hits the ground, sound is produced. Plus, in the question, they stated that the ball bounced to a lower height. This is because some of its Kinetic Energy is lost as heat and sound energy, so i think the answer has to be KE - -> SE + GPE

[Nethan Nerella]

Was there a potential—>kinetic + soumd