13/06/2012 - Experiment #2

I'm back.


Haha, I used the same line in the previous entry, but anyway, I finally had the results. It's currently a little over 2 a.m. now, and I still have to go to school early tomorrow, so you can kind of guess my mood...I'm not really happy about the long experiment time.

Well, I had expected it to be around 2 hours, but obviously it dragged on. And on. And ended up being 6 hours.

So anyway, to cut the long story short, and to let myself wriggle into bed a little earlier, here are the experimental procedures, complete with data and results:

Microwave & Boiling Experiment

Aim of Experiment:

To find out the amount of time water takes to cool down to room temperature after being microwaved or boiled.

Apparatus:

·         1 microwave oven

·         1 1.6l water kettle/boiler

·         1 laboratory thermometer

·         1 500ml measuring cup

·         Tap water

·         1 microwaveable bowl.

Steps of Experiment:

1.       Fill measuring cup with 400ml of tap water.

2.       Pour the measured amount of water into the microwaveable bowl.

3.       Place the bowl into the microwave oven.

4.       Set the timer to default.

5.       Start the microwave oven.

6.       If timer ends, and the amount of water does not reach boiling point of 100°c, steadily increase the timer until a temperature of 100°c is achieved.

7.       If timer ends, and the amount of water is over 100°c, steadily decrease the timer until a temperature of 100°c is reached.

8.       If timer ends, and the amount of water is 100°c, move on to boil water in the boiler.

9.       Fill the boiler with 1.6l of water.

10.   Start the boiler.

11.   Once the boiler has stopped boiling the water, open the boiler.

12.   Measure the temperature of the water in the boiler.

13.   After every half hour, measure the temperature of water in the microwave oven and the boiler respectively.

14.   Conclude experiment when the water reaches room temperature.

Data:

Microwave Oven

Default timer = 4min 40s (maximum time)

Room temperature of water = 30.5°c

Temperature after timer ends = 95°c

Time	Temperature of Water	Comments
5.22.15 p.m. – 5.23.03 p.m.	95°c	-
5.53.03 p.m. – 5.53.39 p.m.	49°c	Possible Anomaly
6.23.39 p.m. – 6.24.20 p.m.	42°c	-
6.54.20 p.m. – 6.54.56 p.m.	37.5°c	-
7.24.56 p.m. – 7.25.39 p.m.	35°c	-
7.55.39 p.m. – 7.56.05 p.m.	35°c	-
Total time: 2h 33min 50s

Note: The time lag is time taken between opening the door of the microwave to closing the door of the microwave.

Boiler – First time

Time taken to boil = 3min 57s

Room temperature of water = 31°c

Temperature after boiling = 99°c

Note: After some of the water was accidentally drunk by my family, the experiment restarted.

Boiler – Second time

Time taken to boil = 3min 52s

Room temperature of water = 31°c

Temperature after boiling = 98°c

Time	Temperature of Water	Comments
7.15.07 p.m. – 7.15.47 p.m.	98°c	-
7.45.47 p.m. – 7.46.32 p.m.	82°c	-
8.16.32 p.m. – 8.17.20 p.m.	71.5°c	-
8.47.20 p.m. – 8.48.05 p.m.	62°c	-
9.18.05 p.m. – 9.18.46 p.m.	56°c	-
9.48.46 p.m. – 9.49.30 p.m.	51°c	-
10.19.30 p.m. – 10.20.16 p.m.	48°c	-
10.50.16 p.m. – 10.50.51 p.m.	45°c	-
11.20.51 p.m. – 11.21.29 p.m.	43°c	-
11.51.29 p.m. – 11.51.56 p.m.	41°c	-
12.21.56 a.m. – 12.22.28 a.m.	39°c	-
12.53.28 a.m. – 12.53.07 a.m.	37.5°c	-
1.23.07 a.m. – 1.23.32 a.m.	36°c	-
1.53.07 a.m. – 1.53.32 a.m.	35°c	-
Total time: 6h 33min 25s

Note: The time lag is time taken between opening the boiler and closing the boiler.  

Conclusion:

Due to restraints in equipment, there will be a difference in 3°c between the temperatures of microwaved water and boiled water. However, it is noted that due to random errors the temperatures of water vary as seen above; thus, the difference is ignored.

Conclusively, the amount of time taken for water to cool down to 35°c would be around 2h 3min 24s in a microwave oven and 6h 33min 25s in a boiler. 35°c is determined as the temperature of water as the water in the microwave oven continues to maintain 35°c after half an hour. This suggests that heated water continues to maintain a temperature of 35°c for a period of time in a microwave oven; thus, the experiment for the boiler is concluded once the water reaches a temperature of 35°c.     

I know the conclusion is really bad, and very unscientific, but I don't think I can continue the experiment any longer. The first one was due to availability constraints with the equipment; the second is due to the fact I really want to be bright and awake for school tomorrow. I'm having a Math lesson teaching us on discriminants and stuff and it's a really important topic, because we're going to have a test on it in Week 2.

*Yawns*. So that's all for now, good night...