Memory Foam Matress

Argent says:

1. [example sentences, for use as a model] Viscosity depends on temperature, in an inverse way. Higher temperature means lower viscosity, since the molecules have enough energy to pull farther away from each other, and therefore not stick to each other very well. Lower temperature has the opposite effect: the molecules can't pull away as well, so they stick better.

2. Cool tar has a very high viscosity, so it doesn't flow well at all. Hot tar flows well.

3. See #1, about cooler liquids and their greater "clinginess".

4. This is somewhat related to viscosity, but more related to surface tension. Water has a moderately high surface tension, so the surface molecules cling moderately strongly. This makes them less able to flow around small objects such as paper clips; instead, their mutual forces make them into a membrane whose tensile strength is as great as the weight of the paper clip.

5. Cohesion is attraction between bits of the same substance; adhesion is attraction between unlike substances.

6.
a.
Substance A moves 20 cm in 2 sec, so its flow is 20/2 = 10 cm/sec.
Substance B moves 20 cm in 10 sec, so its flow is 20/10 = 2 cm/sec.
Substance C moves 20 cm in 5 sec, so its flow is 20/5 = 4 cm/sec.

b. Low-viscosity fluids flow more quickly than high-viscosity fluids. Substance A flows most quickly, so it has the lowest viscosity; the others are rankable per the discussions above.