The Battery Experiment

Friday (02/04/2010)
a) Case Study
* I told them a story to solve the case.
"Jimmy had a big rambutan tree that grows so high and its branches touches the wire cable. There are lots of rambutan fruits near there. How should Jimmy pluck?"

Wei Jeen: Chopped the tree. (...but there won't be anymore fruit in the future).
Devin: Climb. (....but you might get electrical shock).
Chun Kit: Shake the tree. (...but it might pull the wire cable. furthermore, it is too big for you to shake).
Kwong Yong: Carry a ladder. (......but when you pluck with your hands, you might get electrical shock).
Yun Wen: I know....use a long stick pole and tied a knife at its end.
Teacher: Which type of pole is better? Metal? Plastic? Wood? Paper?
Jun Hong: If the metal pole falls on your head, you will get injured.
Shi Jie: Paper is too soft.
Foo Soon: The stick might break.
Teacher: We will do an experiment to figure this out.

b) The Story of Thomas Edison
* When Edison was a 6-year old kid, he started a fire in the barn and many people thought that he was a mischievous and different child. Even the school teacher rejected him after 3 months in class. However, his loving mother bought him a Science Dictionary and he finished reading the whole book. Then, he started making different things. He sold newspaper at fire station and one day as he was trying to hopped into a train, someone pulled his ears to help him up. Unfortunately, his left ear was totally deaf a few yaers later. His right ear was 80% deaf too. One day, he rescued a boy from the railway track and was awarded with a job. His life changed as he found more opportunities inventing things. He improved the bulb because those days, bulb would burn out in a few hours.
* To do this, he experimented more than 10,000 materials for the filament. Finally, he suceeded finding carbon, a type of graphite. Thus, is pencil lead a conductor?

c) Battery experiment.
* I showed them 1.5 V and also 9V batteries. They observed the wires. Then, placed the wire ends to each positive and negative pole of the battery. The kids felt that the battery became hotter. This is "electricity". We placed a piece of small paper but the paper was not hot. We tried out with a piece of granite and it became hotter and hotter. Yun Xin tested with the thermometer and the temperature rose. Further discussions on Monday.........