Q&A - PSLE Science

[Robertpattinsonidle]

ms_lim:

charsen:

[quote=\"ms_lim\"]These are the options for previous post


http://i48.tinypic.com/244qses.jpg\">

Hi
The answer is definetly option 4 as gravitational force is constant on the ball even if the ball is in the air.

Cheeers

Thanks for the confirmation, charsen.[/quote]I disagree. Gravitational force is the same as gravity and gravity does not always be the same. My answer is number 1. When the ball is higher, there will be more gravity acting on it so the graph should be 1. GPE is whereas, the stored energy which follows the gravity right? So i support 1.

[Michaelia0816]

I support 4.

[Michaelia0816]

Need help,


1) Which of one of the following has an adaptation that may reduce its speed when moving in water?
(1) Whale
(2) Penguin
(3) Pufferfish
(4) Seal

[charsen]

Michaelia0816:

Need help,


1) Which of one of the following has an adaptation that may reduce its speed when moving in water?
(1) Whale
(2) Penguin
(3) Pufferfish
(4) Seal

Hi
The answer is pufferfish. It will pop out its spines making the pufferfish look inflated.Since it is inflated,it does not have a streamlined shape body before inflating
Thus,this adaption of inflating reduces the moving speed of the pufferfish.
Cheers.

[Michaelia0816]

Thx Charsen.

[charsen]

Hi robbertpattinsonidle,

Gravitational force is the same.
For example,your friend lives in the 12 th floor and you live in the 39 th floor.
If gravity is the highest in the 39 floor,some of your friends items would be floating in the air.The gravity pull in the earth is the same all the time.Hence, the gravity pull is the same in the 17 floor and 39 floor.Therefore,the gravitational force is acting the same on the ball no matter ho high it is
.Gravitatinal potential energy is another story.
Cheers

[Robertpattinsonidle]

this question part a i got it right. but for part b, i said that the answer is graph c. my science teacher said that it was graph b. but the answer key says graph a. what is the correct answer????? and what is the explanation??? aaargh... its so difficult!!! :skeptical: http://i49.tinypic.com/hw9xdk.jpg\"> http://i47.tinypic.com/s5eels.jpg\">

[Studious Alien]

My answer would be c too... But I'm not an expert

[AceTutors123]

verykiasu2010's answer makes the most sense :salute:

[Way2GO]

The favourable property to look for in the safety vest in this question is visibility over a good range of distances. Only graph C plateau off into the distance. A & B visibility ends abruptly at certain unmentioned distances.

Answer is C.
But I am no science teacher, please confirm with another independent source.