2010 PSLE Discussion

[cafelatte]

Agree with James : Parents have to either learn how to teach their own kids or outsource to the full time tuition professionals.


I like the mindset of KSP parents ! It is good to start early and be prepared. My child not taking PSLE 2010 but I want to ask about:

2010 Chinese Language and HYPY
I read the Subject information on SEAB website. This is the format taken by the schools for current P1-P5. However, I don't see any HYPY specifics in the SEAB description. Anyone knows if there will be HYPY questions in Paper 1 and/or Paper 2 ? Typically, Paper1 and Paper2 will be on the same day with a break(how long?) in between ?

[VitoRelax]

James Ang:

Many adults answered the question wrongly in a simplistic manner reasoning that the friction is opposite in direction to the ball's moving direction, but actually the ball is round so the motion is actually in reverse direction when the ball is moving forward, so the direction of friction is in the same direction of the ball's moving direction.

Yeah, me confused too :?

Can you elaborate on this or are there further readings on this ?

Thanks

[Way2GO]

VitoRelax:

James Ang:

Many adults answered the question wrongly in a simplistic manner reasoning that the friction is opposite in direction to the ball's moving direction, but actually the ball is round so the motion is actually in reverse direction when the ball is moving forward, so the direction of friction is in the same direction of the ball's moving direction.

Yeah, me confused too :?

Can you elaborate on this or are there further readings on this ?

Thanks

The written explanation sounds confusing. It becomes clearer if you do a sketch and visualize it.

[VitoRelax]

Way2GO:

The written explanation sounds confusing. It becomes clearer if you do a sketch and visualize it.

Hey Way2Go, nice to see you back. U came back from overseas holiday liao ?

Yeah, agree with you that the written explanation sounds confusing. I hope there is sketch to help us visualize it !

[Way2GO]

I could do it but I don’t know how to do it in this forum’s format. You just draw a ball…indicate its direction of motion with corresponding friction in opposite direction, then you can see what James means.

[VitoRelax]

Way2GO:

I could do it but I don't know how to do it in this forum's format. You just draw a ball..indicate its direction of motion with corresponding friction in opposite direction, then you can see what James means.

My comprehension in language is not so good lah. U think you can point me to a website where I can read ?

Btw, this science topic is about Pri or Sec school ?

Thanks

[Way2GO]

I think James is referring to P6 Science.

It’s not so difficult to visualize what James is trying to say once you sketch it:
Let me step you thro’ it:
First draw a ball.
Then draw the direction of ball’s roll inside the ball eg clockwise direction.
Next, where the ball contact a flat surface eg, draw the direction of ball forward motion ie left to right like so ->
Then draw direction of friction like so <-
Now can you visualize that friction is in the same direction as the ball’s roll?

[James Ang]

Way2GO:

I think James is referring to P6 Science.

It's not so difficult to visualize what James is trying to say once you sketch it:
Let me step you thro' it:
First draw a ball.
Then draw the direction of ball's roll inside the ball eg clockwise direction.
Next, where the ball contact a flat surface eg, draw the direction of ball forward motion ie left to right like so ->
Then draw direction of friction like so <-
Now can you visualize that friction is in the same direction as the ball's roll?

question no 5, O levels physics 2004
http://www.freeexampapers.com/FreeExamPapers.com_.php?__lo=TyBMZXZlbC9QaHlzaWNzL0NJRS8yMDA0IE5vdi81MDU0X3cwNF9xcF8xLnBkZg==


http://www.postimage.org/image.php?v=Ts13uAnr

[James Ang]

VitoRelax:

Way2GO:

I could do it but I don't know how to do it in this forum's format. You just draw a ball..indicate its direction of motion with corresponding friction in opposite direction, then you can see what James means.

My comprehension in language is not so good lah. U think you can point me to a website where I can read ?

Btw, this science topic is about Pri or Sec school ?

Thanks

O levels Pure Physics question but starting to appear in P6 top school exam papers (NY2009) and P6 assessment books. What is your answer to this question?
http://www.postimage.org/image.php?v=gxGG1BJ

[Way2GO]

My answer:

Frictional force acts from left to right at contact surface between wheel and road.
Direction of wheel spin is counter clockwise.