How do adhesive and cohesive forces explain the observed capillary action for water and mercury in a glass tube?

From the image, the initial water level A is at $24 \text{ mL}$.

From the image, the final level C, after immersing solid B, is at $32 \text{ mL}$.

The volume of the solid is the difference between the final volume and the initial volume.

Since $1 \text{ mL} = 1 \text{ cm}^3$, the volume of the solid is $8 \text{ cm}^3$.

The reading in the solid (volume of the solid) is $\boxed{\text{8.0 mL}}$.

In water, the meniscus in the capillary tube is higher than the meniscus in the beaker, forming a concave meniscus. This occurs because the adhesive forces between water molecules and the glass walls are stronger than the cohesive forces between water molecules themselves. The water molecules are more attracted to the glass, causing them to climb up the tube against gravity.

In mercury, the meniscus in the capillary tube is lower than the meniscus in the beaker, forming a convex meniscus. This occurs because the cohesive forces between mercury molecules are stronger than the adhesive forces between mercury molecules and the glass walls. The mercury molecules are more attracted to each other than to the glass, causing them to pull away from the glass and depress the liquid level in the tube.

Area of hole, $A = 2.0 \text{ cm}^2 = 2.0 \times (10^{-2} \text{ m})^2 = 2.0 \times 10^{-4} \text{ m}^2$.
Depth of tank, $h = 2.0 \text{ m}$.
Density of water, $\rho = 1000 \text{ kg/m}^3$.
Acceleration due to gravity, $g = 9.8 \text{ m/s}^2$.

The pressure $P$ is given by the formula $P = \rho g h$.

The force $F$ is given by the formula $F = P \times A$.

The force on the cork is $\boxed{\text{3.92 N}}$.

Water is a poor conductor of heat. This means that heat does not easily transfer through the bulk of the water by conduction.

Heat transfer in liquids primarily occurs through convection. When water is heated from the bottom, the heated water becomes less dense and rises, while cooler, denser water sinks to take its place, creating convection currents that distribute heat throughout the liquid.

In this setup, heat is applied near the top of the boiling tube. The water at the top heats up, becomes less dense, and boils. However, since the heat is applied at the top, there are no convection currents formed to transfer this heat downwards to the colder water at the bottom. The hot water stays at the top, and the cold, denser water remains at the bottom because it does not receive heat through conduction or convection.