What is the absolute pressure (in kN/m²) in the water just below the meniscus in a capillary tube whose diameter is 0.50 mm? Take the wetting angle as 10°, and atmospheric pressure 100 kN/m².
Answers
Answer:
The pressure just below the meniscus of water is less than just above it due to surface tension and cohesive forces acting on the water surface.
Explanation:
What is surface tension: Definition
In the fall a fisherman’s boat is often surrounded by fallen leaves that are lying on the
water. The boat floats, because it is partially immersed in the water and the resulting
buoyant force balances its weight, as Section 11.6 discusses. The leaves, however, float
for a different reason. They are not immersed in the water, so the weight of a leaf is not
balanced by a buoyant force. Instead, the force balancing a leaf’s weight arises because
of the surface tension of the water. Surface tension is a property that allows the surface
of a liquid to behave somewhat as a trampoline does. When a person stands on a
trampoline, the trampoline stretches downward a bit and, in so doing, exerts an upward
elastic force on the person. This upward force balances the person’s weight. The surface