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Different liquids have different properties. One of these
properties is viscosity, the liquid's resistance
to flowing. Water, milk, and fruit juice are comparatively
thin and flow more easily than thicker, more viscous liquids
such as honey, corn syrup, shampoo, or liquid soap.
Viscosity is an important property of drilling
fluids. A more viscous fluid is better able to suspend
rock cuttings and transport them to the surface. However,
more pressure is needed to pump very viscous fluids, resulting
in additional wear and tear on the drilling equipment. Viscous
fluids are also more difficult to separate from the cuttings.
Temperature affects the viscosity of most liquids. This experiment
focuses on the viscosity of shampoo in a bottle as it is heated
and cooled.
- Clear or light colored shampoo (at room temperature)
- Clear plastic bottle about 444 mL (15 oz) capacity or
slightly larger, with tightly fitting cap [Note: Perhaps
use two plastic bottles of inexpensive shampoo. See step
#2.]
- Stopwatch that measures to 0.1 or 0.01 seconds
- Glass marble small enough to fit through the mouth of
the bottle
- Permanent marking pen
- Ruler
- Hot water (hot water from a faucet is OK)
- Basin large enough for bottle lying on its side to fit
- Cold water
- Ice cubes
- Paper towels
- Safety goggles
- Thermometer (optional)
- Chart like the one below to record your results
1. On the side of the bottle about 3 cm (1 in) from
each end, draw two lines all the way around with a permanent
marking pen. Measure and record the distance between
the lines.
2. Uncap the bottle, insert a marble, fill to the top
with shampoo at room temperature, and close the cap
tightly. [Note: If you have two bottles of shampoo,
you could insert the marble in one, and then pour in
shampoo from the other to fill to the top.]
3. Turn the bottle upside down and observe the marble
as it sinks downward. The marble should come to rest
in the cap. This ensures that the marble will drop down
the middle of the bottle when it is inverted once more.
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4. Invert the bottle once more and use the stopwatch
to measure the time it takes for the marble to sink
down the middle of the bottle from the top line to the
bottom line. Record the time in the Room Temperature
column of the data table opposite Trial 1.
5. Repeat steps #3 and #4 four more times,
for a total of five time measurements. Then calculate
the average time of the marble sinking in shampoo at
room temperature.
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 6.
Next, investigate the viscosity of shampoo at a temperature
higher than room temperature. Fill the basin with hot
water from a faucet or other source. Tighten the cap
on the bottle and place it in the basin so that the
hot water bath can heat up the shampoo. Leave the bottle
in the hot water for about 15 minutes. Carefully turn
the bottle every five minutes or so to heat the shampoo
evenly.
Note: Follow good safety procedures with hot water.
Do not splash hot water around or put your fingers into
it. Please have an adult assist you with this
7. Repeat steps #3 and #4 five times and record the
data in the Warm Shampoo column of the table. Then calculate
the average time of the marble sinking in warm shampoo.
8. What do you think will happen if you cool the shampoo?
Let’s find out. Fill the basin with cold water
and place the bottle of shampoo in it. Add a dozen or
more ice cubes, and stir the water gently. Leave the
bottle in the cold water for about 15 minutes. Carefully
turn the bottle every five minutes or so to cool the
shampoo evenly.
9. Repeat steps #3 and #4 five times and record the
data in the Cold Shampoo column of the table. Then calculate
the average time of the marble sinking in cold shampoo.
Take a look at our results.
10. Optional: Measure and record the temperature of
the shampoo with a thermometer during the three sets
of measurements. Also compare the temperature of the
shampoo to the temperature of the water baths.
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