Science Spark - Spark 4

Science Spark - Spark 4



Link: http://www.sciencemonth.org.sg/spark4.asp
Contest type: Online - Quiz
Prizes: An Acer EeePC 901 Ultraportable PC
Closing date: Not stated
Others:

Question: Two identical beaker of water, Container A at 100 degress, Container B at 30 degress, are placed into the freezer. Which Container will freeze first, or is it C, both freezes at the same time?
Answer: A

This is a controversial question. According to scientist, they have not proven or come up with a theory that can explain the phenomenal.

WHY?
(read only if you want to know)

Hot water freezes faster than cold water is a strange phenomenal that is known as Mpemba effect. It only occurs under certain conditions, only if you get them right, hot water can cool faster than cold water.

It is strange cause the energy required to cool the hot water is much higher than the cold water, and it does not make sense if you calculate the math behind it.

A good explanation of Mpemba effect is due to Evaporation. Hot water promotes evaporation and thus lowering the mass of liquid inside the container and lowering the energy required to cool it. However, Mpemba effect can still be observed in a closed container.

So why does it happen? nobody knows for sure yet.


My comments
Prize’s Value: $1800
Time Spent: 2 mins
Winning rate: Low...

Link by: Ryan