Welcome Guest ( Log In | Register )

Bump Topic Topic Closed RSS Feed
124 Pages « < 101 102 103 104 105 > » Bottom

Outline · [ Standard ] · Linear+

 SPM 2013 Thread

views
     
manutd96
post Oct 5 2013, 11:08 PM

Getting Started
**
Junior Member
184 posts

Joined: Mar 2013


QUOTE(5p3ak @ Oct 5 2013, 05:22 PM)
Hey guys, I got more tips for SEJ SPM (paper 2 IIRC), For form 5 Tema 10 focus on Bab 2 subtopic, Gerakan Islah, Akhbar-akhbar and perjuangan persatuan-persatuan melayu. Tema 11 focus on Bab 5, sistem ahli, bab 6 , pembentukan Malaysia, Akta Malaysia and for bab 8 Memartabatkan BM and Dasar kebudayaan. For Tema 12(bab 9) look out for Dasar Luar Malaysia and Cabaran Masa depan especially K Ekonomi and K masyarakat.

Hope this helps smile.gif
Okay whatever floats your boat...if you insist I am BU3 then BU3 I am to you then. biggrin.gif
*
U are from bu4 la dont lie.. I know ur form 1 class is 1 daisi
Screen
post Oct 5 2013, 11:10 PM

.
******
Senior Member
1,254 posts

Joined: Oct 2011
Guys, mind helping out on a few questions here?

1st pic: Question 9
2nd pic: Question 3 and 4

» Click to show Spoiler - click again to hide... «

manutd96
post Oct 5 2013, 11:23 PM

Getting Started
**
Junior Member
184 posts

Joined: Mar 2013


QUOTE(Screen @ Oct 5 2013, 11:10 PM)
Guys, mind helping out on a few questions here?

1st pic: Question 9
2nd pic: Question 3 and 4

» Click to show Spoiler - click again to hide... «

*
2b, 3c, 4 ( try) b right? Nt sure about 9.
Critical_Fallacy
post Oct 5 2013, 11:32 PM

∫nnộvisεr
Group Icon
VIP
3,713 posts

Joined: Nov 2011
From: Torino
QUOTE(Screen @ Oct 5 2013, 11:10 PM)
1st pic: Question 9
Q9 requires you to calculate the pressure at the base of the tank due to water.

And you seemed to know the formula Pressure = Force (or Weight) / Area.

You have calculated the mass of water (m) is 1050 kg. Can you find the weight of water? sweat.gif
Screen
post Oct 5 2013, 11:48 PM

.
******
Senior Member
1,254 posts

Joined: Oct 2011
QUOTE(manutd96 @ Oct 5 2013, 11:23 PM)
2b, 3c, 4 ( try) b right? Nt sure about 9.
*
Mind explaning it, I don't know the answers too

QUOTE(Critical_Fallacy @ Oct 5 2013, 11:32 PM)
Q9 requires you to calculate the pressure at the base of the tank due to water.

And you seemed to know the formula Pressure = Force (or Weight) / Area.

You have calculated the mass of water (m) is 1050 kg. Can you find the weight of water? sweat.gif
*
What I did:
» Click to show Spoiler - click again to hide... «

Critical_Fallacy
post Oct 5 2013, 11:58 PM

∫nnộvisεr
Group Icon
VIP
3,713 posts

Joined: Nov 2011
From: Torino
QUOTE(Screen @ Oct 5 2013, 11:48 PM)
What I did:
Your approach is correct, but lacking experience.

Try multiply the mass of water with g = 9.8 m/s². icon_idea.gif
Screen
post Oct 6 2013, 12:43 AM

.
******
Senior Member
1,254 posts

Joined: Oct 2011
QUOTE(Critical_Fallacy @ Oct 5 2013, 11:58 PM)
Your approach is correct, but lacking experience.

Try multiply the mass of water with g = 9.8 m/s². icon_idea.gif
*
Owh, I get it now.

Mind helping out on the other 2 questions?
5p3ak
post Oct 6 2013, 07:53 AM

CPE, FIG Certified Gymnastics Coach
*******
Senior Member
5,648 posts

Joined: Mar 2011
From: Jalan Tijani
QUOTE(stpxdf88l @ Oct 5 2013, 07:17 PM)
I was just saying. Haha, I'm sorry if I offended you!
*
wat . You also didn't meant me harm why apologise laugh.gif

QUOTE(manutd96 @ Oct 5 2013, 11:08 PM)
U are from bu4 la dont lie.. I know ur form 1 class is 1 daisi
*
I said

QUOTE(5p3ak @ Oct 5 2013, 05:22 PM)
Okay whatever floats your boat...if you insist I am BU3 then BU3 I am to you then. biggrin.gif
*
I never said I am actually from BU3. He like me to be from Bu3 then so be it. I don't mind laugh.gif Btw you are?

QUOTE(Screen @ Oct 5 2013, 11:10 PM)
Guys, mind helping out on a few questions here?

1st pic: Question 9
2nd pic: Question 3 and 4

» Click to show Spoiler - click again to hide... «

*
That 2nd question in 2nd pic answer label wrong or memang mcm tu? A -> C then B? hmm.gif

I believe question 4 is B. didn't see the numbering properly lol

This post has been edited by 5p3ak: Oct 6 2013, 01:06 PM
Critical_Fallacy
post Oct 6 2013, 09:26 AM

∫nnộvisεr
Group Icon
VIP
3,713 posts

Joined: Nov 2011
From: Torino
QUOTE(Screen @ Oct 6 2013, 12:43 AM)
Mind helping out on the other 2 questions?
Q3

Purpose:
Find the tension in the rope that holds the hot air balloon in equilibrium (static).

Understanding:
The balloon floats because of the buoyant force (from the surrounding air) exerted on it. Without the rope, the balloon will slowly lift up high into the air, because the pressure difference between the top and bottom of the balloon results in a net force that tends to accelerate an object upwards. That's the buoyancy effect.

Solution:
The tension in the rope = the net force (lift) = Buoyancy force (↑) − weight of balloon due to gravity (↓)

Buoyancy force = Weight of air displaced by the balloon

Can you do Q4 using Archimedes' principle? sweat.gif
kangaroo96
post Oct 6 2013, 10:15 AM

New Member
*
Junior Member
33 posts

Joined: Sep 2013
for Q9 is it a very direct question where Pressure = Depth x Density x 9.8

P = 0.7 x 1000 x 9.8 = 6860 Pa?

This post has been edited by kangaroo96: Oct 6 2013, 11:02 AM
Critical_Fallacy
post Oct 6 2013, 11:01 AM

∫nnộvisεr
Group Icon
VIP
3,713 posts

Joined: Nov 2011
From: Torino
QUOTE(kangaroo96 @ Oct 6 2013, 10:15 AM)
for Q9 is it a very direct question where Pressure = Depth x Density x 9.8

P = 0.7 x 1000 x 9.8 = 6860 Pa?
The pressure formula P = hρg (for fluid) can be derived from P = W / A.

weight, W = mg

mass, m = ρV

volume, V = hA

In fact, if the question asks for the total pressure below the base of the water tank due to the compression load on the concrete foundation, then the formula P = hρg is not sufficient. icon_idea.gif
Heartnsoul
post Oct 6 2013, 11:41 AM

Going through hell? Keep going!
*****
Senior Member
889 posts

Joined: Sep 2013
From: Penang


QUOTE(Screen @ Oct 5 2013, 11:10 PM)
Guys, mind helping out on a few questions here?

1st pic: Question 9
2nd pic: Question 3 and 4

» Click to show Spoiler - click again to hide... «

*
Question 9, the answer should be A, 1m X 1.5m X 0.7m and you get 1.05 m^3. Using the density you get 1050kg. Multiply by 9.8 and you get 10290 N acting on the base. Pressure = Force / Area . Sub 10290 into F and 1.5 into area and you get your pressure 6860 Pa.

or we could just use the P=hpg method?

For the second picture, Q3 should be C, as the force pushing it up is 15000 N while the the weight is 800 N, thus it has a resultant force of 7000 N which is canceled out by the tension of the string/rope whatever at 7 X10^3 N. For Q4, Archimedes' principle. rclxms.gif

This post has been edited by Heartnsoul: Oct 6 2013, 11:58 AM
TSmaximR
post Oct 6 2013, 11:54 AM

Remember who you are
*******
Senior Member
3,864 posts

Joined: Dec 2009



QUOTE(manutd96 @ Oct 5 2013, 09:47 PM)
Why B? I have done similar ones before too.
*
I'm sorry , I was meant to type D . sweat.gif Sorry for the confusion .
Heartnsoul
post Oct 6 2013, 12:05 PM

Going through hell? Keep going!
*****
Senior Member
889 posts

Joined: Sep 2013
From: Penang


MaximR, what do you think of Screen's second picture, question 4. I assumed the answer was B, then I remembered about the mass of the objects. Do you think it is A or B? Have not work on my Physic in a while and the add. math I have been doing is really making me blur at the moment rclxub.gif

Edit : Could not find a similar question in both of my reference books rclxub.gif

This post has been edited by Heartnsoul: Oct 6 2013, 12:13 PM
TSmaximR
post Oct 6 2013, 12:29 PM

Remember who you are
*******
Senior Member
3,864 posts

Joined: Dec 2009



QUOTE(Heartnsoul @ Oct 6 2013, 12:05 PM)
MaximR, what do you think of Screen's second picture, question 4. I assumed the answer was B, then I remembered about the mass of the objects. Do you think it is A or B? Have not work on my Physic in a while and the add. math I have been doing is really making me blur at the moment rclxub.gif

Edit : Could not find a similar question in both of my reference books rclxub.gif
*
Tension = Upthrust - Weight of object = Weight of water displaced - Weight of object

Since the objects will float when the tension is removed , Upthrust > Weight of object

So , based on my reasoning , since the mass of 3 > 2 > 1 , weight of 3 > 2 > 1 ,

T3 > T2 > T1

[ Ans : B ]

Critical_Fallacy

Is my reasoning correct ?

This post has been edited by maximR: Oct 6 2013, 01:00 PM
Critical_Fallacy
post Oct 6 2013, 12:58 PM

∫nnộvisεr
Group Icon
VIP
3,713 posts

Joined: Nov 2011
From: Torino
QUOTE(maximR @ Oct 6 2013, 12:29 PM)
Tension = Upthrust / Buoyant force = Weight of water displaced by object = Weight of object ( since they're completely submerged )

So , based on my reasoning ,

T3 > T2 > T1

[ Ans : B ]
Although your answer B is correct, it is worthwhile to mention that, the weight of water displaced by a fully immersed polystyrene DOES NOT equal to the weight of the polystyrene, unless it floats freely on the water surface.

The weight of the polystyrene is negligible (0 N) because it has very low density.

Thus, we have

Tension = Weight of displaced water − 0.

Assuming that all Polystyrene (P) have the same cross section area, so volume of P3 > P2 > P1.

Since the parameters of water density and standard gravity, g are unchanged, then tension T3 > T2 > T1. icon_rolleyes.gif

This post has been edited by Critical_Fallacy: Oct 6 2013, 01:02 PM
TSmaximR
post Oct 6 2013, 01:02 PM

Remember who you are
*******
Senior Member
3,864 posts

Joined: Dec 2009



QUOTE(Critical_Fallacy @ Oct 6 2013, 12:58 PM)
Although your answer B is correct, it is worthwhile to mention that, the weight of water displaced by a fully immersed polystyrene DOES NOT equal to the weight of the polystyrene, unless it floats freely on the water surface.

The weight of the polystyrene is negligible (0 N) because it has very low density.

Thus, we have

Tension = Weight of displaced water − 0.

Assuming that all Polystyrene (P) have the same cross section area, so volume of P3 > P2 > P1.

Since the parameters of water density and standard gravity, g are unchanged, then tension T3 > T2 > T1. icon_rolleyes.gif
*
Edited my post above , forgotten the fact that Tension = Buoyant force - Weight of object ( net force on object )

Thank you . These questions serve as good practices ; I realise I will need to re-visit certain concepts . nod.gif
TSmaximR
post Oct 6 2013, 01:11 PM

Remember who you are
*******
Senior Member
3,864 posts

Joined: Dec 2009



Critical_Fallacy

I have an old past year paper book --- so I have no choice but to upload those original ones in B.M .
Can you help me with this ? [ Q 39 ]

user posted image

Thanks !
Critical_Fallacy
post Oct 6 2013, 01:18 PM

∫nnộvisεr
Group Icon
VIP
3,713 posts

Joined: Nov 2011
From: Torino
QUOTE(maximR @ Oct 6 2013, 12:29 PM)
So , based on my reasoning , since the mass of 3 > 2 > 1 , weight of 3 > 2 > 1 ,

T3 > T2 > T1
Just want to be more specific. Because we are calculating the weight of the displaced water, W = mg,

where m, the mass of the displaced water is given by m = ρV, we have W = ρVg.

Therefore, it is easier to reason with the Volume of the displaced water because we can justify the volume of an object by vision alone. For mass, we need to measure since it is a fundamental physical property.
TSmaximR
post Oct 6 2013, 01:19 PM

Remember who you are
*******
Senior Member
3,864 posts

Joined: Dec 2009



QUOTE(Critical_Fallacy @ Oct 6 2013, 01:18 PM)
Just want to be more specific. Because we are calculating the weight of the displaced water, W = mg,

where m, the mass of the displaced water is given by m = ρV, we have W = ρVg.

Therefore, it is easier to reason with the Volume of the displaced water because we can justify the volume of an object by vision alone. For mass, we need to measure since it is a fundamental physical property.
*
Noted with thanks . smile.gif

124 Pages « < 101 102 103 104 105 > » Top
Topic ClosedOptions
 

Change to:
| Lo-Fi Version
0.0299sec    0.90    6 queries    GZIP Disabled
Time is now: 14th December 2025 - 03:19 PM