Physics Project-Mpemba
Effect
Jack Mu, Phillip Ji
Question: Whether the warm water
freezes faster than cold water inside a
fridge or the cold one freezes faster than
the warm one?
Hypothesis: warm water can freeze faster
than cold water inside a fridge.
Settings+Measuring tools:
• beakers
• thermometers
• water furnace
• stopwatch
• electrical balance
• fridge
• dropper
Procedure:
• Pour 50g water with different temperature(23.3℃, 45℃, 65℃, 75℃)in each
identical beakers
• Put the beaker in the fridge for 140 minutes.
• Measure the mass of the ice after taking out the beakers from the fridge.
• Repeat the steps above for 3 times.
Controlled variable: mass of water, time in the fridge, size of beakers
Independent variable: temperature of water
Dependent variable: mass of ice formed by water
Result:
Data collected:
Experient 1
Experient 2
Experient 3
average
23.3
2.40
1.74
1.37
1.84
45
5.82
5.30
3.33
4.81
65
1.58
5.00
1.91
2.83
75
3.22
2.00
0.10
1.77
temperature(℃)
mass of ice(g)
Data Analysis:
Discovery:
• 热水与冷水形成的冰质量比温水所形成的要小。
• 热水水分子运动能量更大，冷水水分子运动能量更小，而温水水分子运动能
量适中，导致温水水分子能量消耗更多，因为热水容易蒸发，冷水水分子更
稳定，温水更能够结冰。
• 当水处于某一个适中的温度时，所形成的冰最多。
• Mpemba发现热牛奶比冷牛奶更快结冰有可能牛奶属于混合物，蛋白质会影
响水结冰。
Errors:
• Random errors:
1.air is in the water
2.temperature of water can drop down before sending beakers into the fridge
3.ice melt before measuring the mass
4.water evaporate(not send the beaker to the fridge quickly) → mass loss
• Systematic errors:
1.cannot accurately read the temperature from the thermometers
2.there’s other substance in water(beakers are not washed totally)
3.the temperature in the fridge is not stable and balanced
4.the length of time when beakers are kept in the fridge is different