Page 138 - Physics
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Physics for Secondary Schools
Acti vity 6.5 Ethanol rises to the highest height
while water rises the least. This
Aim: To observe capillarity in different suggests that ethanol has the
liquids. strongest adhesive force than
water and cooking oil. Also,
Materials: Beakers, 0.5 mm glass tubes, ethanol has the lowest density.
water, cooking oil, ethanol This means that capillary action
Procedure is greater in ethanol.
1. Fill three beakers about half full of water, Applications of capillarity
ethanol, and cooking oil.
2. Immerse a glass tube of 0.5 mm diametre into 1. Capillarity is essential to
plants and animals. In plants,
each liquid; make sure that the base of the it facilitates the transportation
glass tube in each liquid is at the same level, of water and nutrients from
as shown in Figure 6.16. the roots to the leaves. In
0.5 mm tubes animals, it assists in the
circulation of blood.
2. Capillarity promotes the
movement of groundwater.
This is in addition to the
gravitational movement of
water in the soil.
3. It is the principle on which
paper and fabric towels work
to absorb water. For example,
Water Ethanol Cooking oil soaking up moisture from the
Figure 6.16 body using a towel is due to
capillary.
3. Measure and record the height of each
liquid above the surface of the liquid in 4. Clothes worn in hot climate
the beaker. conditions use capillary
action to draw perspiration
Questions away from the body.
(a) Which liquid rose to the highest height? 5. In an oil or kerosene lamp,
(b) Which liquid had the least rise in height? capillarity draws fuel up
(c) Explain what this suggests about the adhesive into the wick where it can
and cohesive forces in each liquid. be burnt.
132
Student’s Book Form One
Physics Form 1 Final.indd 132 16/10/2024 20:57
