Sunday, 3 August 2014

Think 3, 4 and 5

Think 3

Macro
The tiles are worse thermal conductors than parquet. Thus the right feet will lose thermal energy to the tiles faster than to the than the left feet losing thermal energy to the parquet, therefore the feet on the tiles feels colder than the feet on the parquet.


Think 4
Group Answer
The thermal energy from the hot water will be transferred to the metal surface of the cup, and then transferred to the cold water. Thus the hot water will decrease in temperature, while the temperature of the cold water increases. After that, the temperature in which the two water meet will be room temperature.
Individual Answer
Thermal energy is transferred from a hotter region to a colder region. Therefore since the hot water in the metal cup has a higher temperature of 70 Degree Celsius, the thermal energy of the water in the metal cup will be transferred to the metal cup, and then to the colder water. The water in the metal cup will thus decrease in temperature, while the water outside the metal cup will increase. The thermal energy rate of transfer will decrease as the difference between the two water temperature becomes smaller, therefore the line of the rate of decrease in temperature is a curve. The thermal energy transfer between the water in and outside the metal cup will stop when they reach thermal equilibrium, at 32.5 Degree Celsius. The temperature of the water will not reach at room temperature in the end as the styrofoam cup is a poor thermal conductor, therefore it is able to minimise the effect of the room temperature on the temperature of the water. 

Think 5
We can apply heat to the ring.

The inner diameter of the ring will increase or decrease as the thickness of the ring increase or decreases respectively. 
Explanation: The thermal energy of the heat source will be transferred to the ring, therefore the ring will increase in temperature, and the molecules will gain more kinetic energy and vibrate faster, and the thickness of the ring will increase. This will then cause the inner diameter of the ring to expand in length as well.
With the same concept, when the ring is left for cooling, the temperature of the ring will decrease and the kinetic energy between the molecules will decrease and vibrate lesser. Therefore the thickness of the ring will decrease, and will lead to a decrease in the inner diameter of the ring. 





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