Wednesday 29 May 2013

SIP appendix

Pictures of green bean seeds over duration of the experiment:

Set-up A: set-up with pop music played

Set-up B: set-up with classical music played

Set-up C: control. Set-up without music.

Day 1: start of the experiment 

Day 1 results: 
- A : 0
- B : 0
- C : 0

Day 3: 
Top left: A      Middle: B    Top right: C

For safety issues, the containers were brought indoor while the earpieces were placed inside set-up A and B ( during the 'music-hearing' session) . After the music was played for 1.5 hours, the set-ups were then placed outdoors again for sunlight. 
Day 2 results:
A: ( 5 + 5)/ 2= 5mm ( average of two plants) 
B: 0
C: 0 
Day 4: 
Set-up A. The seeds on the top and top right hand of the container have germinated.
Set-up B. No seeds germinated yet

Set-up C. No seeds germinated yet.


Day 4 results:
A: ( 5+ 15)/2 = 10mm
B: 0
C: 0

Day 5: 
Set-up B. One seed germinated


A closer view of set-up A's seedling


Set-up A


As there was still no sign of germination for set-up C, it looked the similar to  previous days,  hence no pictures were taken.

Day 5 results: 

A: (60+ 20 )/2 = 40mm
B: 10mm
C: 0

Day 6:



From top to bottom: set up A, B then C.
Day 6 results:
A: ( 105+ 25)/2 = 65mm
B: 15mm
C: 2mm


Day 7:
Set-up A
Set-up B
Set-up C
Day 6 results ( final):
A: (150+50)/2 = 100mm
B: 15mm
C: 2mm

Sunday 26 May 2013

Marble Run


22/5/13
We were tasked to design and build a pathway for a marble from te top left hand corner to the bottom right hand corner on a sloping board. The team who makes the marble's journey last as long as possible wins! :)
Our Final Design!

Final Result: 11 seconds

Reflections
I think that our timing could have been better if we had build our pathway longer, like how other groups did. As our pathway was much shorter than the other groups, there was a difference in timing. However, i believe that our speed was most probably similar to other groups. 
Speed = Distance/ Time
To increase time = increase distance
decrease time = increase friction and/or decrease gradient of slope

The most difficult part of this Challenge was making sure the ball stayed on track and is in constant motion. I really liked how our product turned out overall as our ball successfully cleared the course! :)

Application to The Real World

Three types of guiding structure:
- Mountain Road
-River flow ( concave and convex banks)
- Marathon. ( where the runners follow the sign board to run)

Kinds of kinetic energy:      
- Rotational Kinetic energy ( e.g. like how the Earth Rotates! :)


Tallest Free Standing Structure

20/5/13
So we were assigned to build the Tallest Free Standing ( at least 10seconds) using only NEWSPAPER and SCISSORS


It sounded quite impossible to me at first but after discussing as a group and planning out our structure, our structure was actually quite successful ! :)  We didnt manage to capture a picture of our end product though ><

Our FInal design was to create a cone-like base such that it would be able to sustain the heavy weight of the upper body of the tower. We stuffed balls of newspaper under the cone to increase its weight and that it would not topple over easily. 
For the upper body of the tower, we rolled up thin pieces of newspaper and connected it to one another . As we were building up the tower, we decreased the size of the newspaper roll so that the weight of the upper body would not be heavier than the lower body such that the entire tower will topple over due to gravitational forces. Our tower kind of looked like the eiffel tower with its triangular shape.


Concepts behind the tower:

The strength of a building material can depend on how it is used. Pleating or rolling paper can increase its stiffness. By crumpling, folding, and otherwise reshaping the flimsy flat sheets and by forming a wide base, students can make their newspaper sheets in this activity stand up and reach unexpected heights
Many forces are at work on towers. Gravity and the dead load of a towers will push down, the ground pushes back up, and small air movements push from the side. A foundation distributes the load into the surrounding ground material and can help balance the sideways wind force. The size of the foundation depends on the strength of the supporting ground. A foundation placed in rock can be smaller than a foundation placed in sand or mud.
( taken from: http://teachers.egfi-k12.org/lesson-build-a-tower/) 

More reads: :)
http://www.pbs.org/wgbh/buildingbig/skyscraper/index.html

Thursday 28 March 2013

Chemical Changes

Chemical Change:


  • process that produces new substance (s)
  • Particles of substance are broken apart
  • Atoms are rearranged into new particles, forming a new substance

Types of Chemical Changes/ Reaction:

  • Combination -> 2 or more elements combine to form a new product compound involving energy change
  • Combustion-> a substance burns in oxygen to produce new product (s)
  • Thermal (heat) Decomposition-> A compound breaks down into 2 or more smaller substances
  • Precipitation -> 2 aqueous solutions are mixed to form one solid product (precipitate)
  • Photosynthesis
  • Respiration
How to define if its  a chemical/ physical change

INFORMATION ON WORD EQUEATION:


Burning 
This is when a substance reacts with oxygen and produces a flame.
Burning always produces an OXIDE.
Burning an element produces ONE oxide.
Burning a compound produces TWO or more oxides.
The mass of the oxides formed will always be MORE than the mass of the substance being burned. (why?)
eg i. Burning magnesium
Burns with bright white flame to form magnesium oxide
Word equation: Magnesium + oxygen ----> magnesium oxide
Burning Methane (natural gas)
Methane is a COMPOUND of carbon and hydrogen. (ie a hydrocarbon. other hydrocarbons are wax, petrol)
It burns with a smoky flame to form carbon dioxide and water
Word equation: Methane + oxygen ------> carbon dioxide and water
Alcohol will also burn to form carbon dioxide and water.
This is when a compound splits apart and forms two (or more) new substances.. (Each of the new substances contains atoms that was there to start with)
note : Elements can NEVER decompose because they are only contain ONE kind of atom.
Each new substance formed will have LESS mass than the original substance
eg i. Heating copper sulphate
Copper sulphate DECOMPOSES and forms water vapour, leaving white anhydrous copper sulphate.
Word equation: Hydrated copper sulphate ----> anhydrous copper sulphate + water
NOTE: This reaction is reversible. If water is added to anhydrous copper sulphate then the solution turns blue again accompanied by a rise in temperature.
Heating copper carbonate The copper carbonate DECOMPOSES forming carbon dioxide gas and leaving copper oxide. 
Word equation: Copper carbonate ----> copper oxide + carbon dioxide
iii. Heating limestone
The limestone decomposes and forms LIME and carbon dioxide gas
Word equation: Calcium carbonate -----> calcium oxide + carbon dioxide
or Limestone -----> lime + carbon dioxide

Reactions in Biology
 i Respiration 
Respiration is the reaction that takes place in ALL living organisms that releases energy from sugar. This energy is used by the organisms for essentials like growth, movement and warmth
Word equation: Glucose + oxygen ----> carbon dioxide + water
ii Photosynthesis
This is the reaction that takes place in the chloroplasts (found mainly in leaves) of plant cells
It converts carbon dioxide and water into sugar and starch, using energy from the sun.
Word equation    Carbon dioxide + water -----------> glucose + oxygen 
(Chlorophyll+ sunlight)


Precipitation 
e.g. lead (ll) nitrate + potassium iodide -> potassium nitrate + lead (II) iodide

Combination :
e.g. Potassium + chlorine gas -> Potassium chloride


JUST FOR LAUGHS :D

Physical Phenomena

Types of Physical Phenomena:


Heat gained: 

  • Melting
  • Boiling
  • Evaporation
  • Sublimation
Heat loss:
  • Freezing
  • Condensation
  • Deposition
Others:
  • Dissolving
  • Diffusion

Physical Phenomena can be explained through Kinetic Particle Theory:

Example of heat gained ( Melting ):
Particles in solid only vibrate in fixed positions due to strong forces of attraction holding them closely together.
Upon heating, heat energy is absorbed by the particles of the liquid. The heat energy is converted into kinetic energy. The particles move faster as the temperature rises. When the temperature is high enough to reach melting point of water, the heat energy taken in is used to overcome the forces of attraction holding the particles together.
After melting is completed, heat energy is taken in to increase the kinetic of the particles, which now slides past each other continuously at a higher average speed.

Example of heat loss (Desublimation):
Particles in gas state move far apart from each other in a random direction and constant motion.
Upon cooling, heat energy is loss and the particles lose kinetic energy. The particles move slower as the temperature decreases. When the temperature os low enough to reach the desublimation point, the attractive forces of the particles strengthen as the particles does not have sufficient energy to overcome the forces.
After desublimation is completed, heat energy loss decreases the kinetic energy of the particles which vibrate in fixed positions in constant motion at a slower average speed due to strong attractive forces holding them close together.

Diffusion:
      Diffusion of a substance eg. a drop of ink in a glass of water; is evidence of matter being made up of tiny particles in constant random motion.
    When a drop of ink is added to a glass of water, it is observed that the ink spreads to different parts of the water without the need to stir.
   If particles are not already moving constantly, the ink would not be observed to spread on its own.
    There is no fixed pattern or direction to the movement/spread of the ink, indicating that the movement is random.


Assumptions and Limitations.

However, there are Limitations and Assumptions are made when using KPT model to explain the physical phenomena.


Assumptions:
(refer to handout given)
Limitations
(refer to handout given)




Friday 8 February 2013

Theory- Kinetic Particle Theory 8/2/13

Kinetic Particle Theory

Explained by:
  • diffusion
  • inter conversion of states
  • Brownian Motion
Represented through:
  • kinetic particles model
          -> explains particles' motion and arrangement in 3 states of matter

Example of particle motion

Physical Properties!! ( things that CAN be measure )

  1. Volume
  2. Mass
  3. Density
  4. Conductivity
x SHAPE    
x SIZE 

Mini Quizzz:

Use KPT to explain what happens to the particles
  1. When an ice cubes melts
  2. When water boils
When heat is supplied, water molecules gain energy and vibrate faster about their fixed position
When solid water molecules gain sufficient energy to overcome the hydrogen bonding that hed them in fixed positions,
the water molecules will move slightly apart and now roll and glide over each other (LIQUID)

Water  molecules gain energy, they move faster and further apart
When water molecules gain sufficient energy to completely overcome the hydrogen bonding between the molecules,
the water molecules move far apart and away from each other . (GAS)

melting point/ boiling point --> shows that heat is about to break up the bonding
* bond between water molecules = hydrogen bond 

Condensation
  • loses heat to the surrounding
  - forms bonds

* think about freezing , condensation and sublimation

3 states of matter at different temperatures:


Thursday 7 February 2013

Kinetic Particle Theory 7/2/13



Investigating Diffusion in Matter





3 main points of experiment:

  • spaces between particles
  • Particle molecules in constant, random motion 
  • Substance with greater mass ( heavier ) moves much slower --> slower diffusion rate.

forces of attraction between particles
solid > liquid > gas

energy of particles:
solid < liquid < gas

e.g. : With greater energy, gas is able to overcome the forces of attraction between particles and thus move freely.

KPT limitation:
--> electrical conductivity ( does not explain)

Assumptions:
-> particles have kinetic energy
-> particles are in constant, random motion
-> forces of attraction between particles.