Tajuk : Sifat-Sifat Jirim (State of Matter)
Bahan-bahan yang diperlukan:
1) Tepung jagung
2) Air
3) Mangkuk plastik
Prosedur:
1) Masukkan tepung jagung ke dalam mangkuk plastik kira2 dan larutkan dalam air. Nisbah tepung dengan air ialah 1-1/4 tepung dengan 1 cawan air. (Pandai-pandai agak biar tepung tu dalam keadaan tak cair dan tak keras sangat)
2) Uli dengan tangan. Kemudian, bentukkan tepung menjadi bulat dengan tangan. Anda akan dapati tepung tu keras.
3) Kemudian, cuba lepaskan genggaman tangan. Tepung tadi akan cair.
Penerangan Sains:
The way that a liquid flows or moves is affected by its viscosity. Quicksand and the cornstarch-water mixture are both non-Newtonian fluids, meaning that their viscosity changes with the type of force applied to it. Unlike quicksand, the viscosity of Newtonian fluids (fluids, such as water and honey, that follow Sir Isaac Newton's law of viscosity) is dependent only on the temperature and pressure of the fluid, not the force applied to it. For instance, warm honey flows much more freely (less viscous) than cold honey (more viscous).
Since the ability of a non-Newtonian fluid to move depends on the force or stress applied to it, these fluids do not act like ones we are more familiar with (e.g. water). A light pressure, such as pouring or gently pressing the cornstarch-water mixture, allows it to move like a liquid. But a high pressure, such as punching firmly, causes the cornstarch-water mixture to act as a solid. This same principle applies to quicksand. When it is lightly stepped on by the unaware adventurer, the quicksand liquefies and the foot of the adventurer starts to sink. Panicking, the adventurer tries to quickly pull his or her foot out, only to find that now the quicksand is acting like a solid, encasing the foot all the more firmly in this unpredictable substance. Ada faham???
But don't worry about get sucked down into quicksand like you see in the movies. Although humans do initially sink when they first enter quicksand, they cannot sink all the way (only to about chest deep). This is because humans are less dense than quicksand. One way to get out of quicksand is to lay back on it and float, much like you would do in regular water. If you have just a foot stuck in quicksand, gently move the foot back and forth, adding water along the side of your leg. This will help the quicksand to act more like a liquid and release your foot.
Last but not least..MasyaAllah hebat ciptaan Allah =) Selamat mencuba
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