Monday, 11 August 2014

Think 6

Question:
Group Answer:
My Answer:
After both strips are heated, it is observed that Metal B expanded more than Metal A . This is due to Metal B having more electrons than Metal A to allow transfer of Thermal energy to take place more quickly in B. When transfer of thermal energy takes place more quickly, Metal strip B will expand first, pulling metal A along, resulting in a bend. A bend means one metal expanded faster than the other. 

When cooled, it is observed that Metal B lose thermal energy at a faster rate than A since B had more electrons. This allowed Metal B to contract back to its original position first, pulling the bent Metal A along. Thereofore, the strip is straightened.






Friday, 1 August 2014

Think 5


Individual Answer:
Heating:
Since gas expands faster than solids, the rate of EXPANSION of the air space would be faster than the rate of expansion of the ring, causing the air in the space to push A outwards, widening the gap for ball to pass through.
Cooling:
Since gas contract faster than solids, the rate of contraction of the air space would be faster than the rate of contraction of the ring. Hence, the ring becomes thinner, the air space would be smaller for ball to pass th.

Conclusion: Heat the ring.

Notes On Chapter 9.1-9.2

Kinetic Theory(MICROSCOPE) LAW 
Whether it is solid/liq/gas, the theory says looking at  these through a microscope you can only see molecules. Molecules are always MOVING. 

SOLID MOLECULES CANNOT MOVE, THEY CAN ONLY VIBRATE.(ABOUT A FIXED POSITION) >>Motion

LIQ MOLECULES can MOVE
GAS MOLECULES(distance a lot, move very fast)

Density SAME. (Amt of substance is same; the factor that tells apart the motion of 3 states is the size of part)

Temperature is the measurement of the av kinetic energy. 
30degrees 
Heating take place 
Molecules move faster-->  temp higher(50degrees)

At absolute Zero, the mole will not freeze. The mole will just stop moving. (273degrees) 

KeyWords To Be Used in Test!!


THERMAL ENERGY FLOWS FROM A HOT OBJ TO A COLD OBJ. 
THERMAL EQUILIBRIUM
TEMP DIFFERENCE

Thursday, 31 July 2014

Think 4


Cold water's temperature increase while hot water's temperature decrease. 
The rate of increase/decrease is different. The rate of decrease is faster than the rate of increase as metal is a better thermal energy conductor, causing thermal energy to be lost to the cold water at a faster rate. The upper curve showed faster rate of flow of TE.

Why is metal and styrofoam cup used respectively? 
MetalCup---Allow speedier transfer of thermal energy from the hot water to the cold water so as to speed up the rate of thermal energy gain and loss

StyrofoamCup---Reduce(not prevent)the cold water from gaining heat from surroundings. This ensure that room temperature does not play as a factor to affect the experiment. 

When the question is little open, you need to make assumptions so that you can narrow the possibilities.

The hot water is losing TE from the room temperature and the cold water. Visa Versa; the cold water is gaining TE from the room temperature and the hot water. In other words, using styrofoam cup help eliminate the room temperature.


Think 3




Tiles are better thermal conductors than parquet {1st point}
Explain what a better thermal conductive is? {2nd Point}
Answer: The material which remove TE from your feet at a faster rate. 

 Thinking Process:
Room Temp: 28degrees (linked to the temp of flooring)
Body Temp:  37degrees

Tiles feel cold because there is a greater difference between your body temperature and the room temperature than parquet causing thermal energy to be removed at a faster rate.