When you accidentally overfill a water glass, the water takes on a dome-like or convex shape, but a half-filled water glass takes on a concave shape, in which the water is higher at the sides of the glass. This is because:

Within the glass, adhesive forces dominate, and on top of the glass, cohesive forces dominate.

Within the glass, water tries to maximize its surface area, and on top of the glass, water tries to minimize its surface area.

Water's surface tension is greater inside the glass than on top of the glass.

Adhesive forces between water and the glass get weaker with height.

The water is higher at the sides of the glass. This is because within the glass, adhesive forces dominate, and on top of the glass, cohesive forces dominate.

Answer Link

RomeliaThurston RomeliaThurston · Answer 2 · 2019-08-28T09:59:17+02:00

Answer: The correct answer is within the glass, adhesive forces dominate, and on top of the glass, cohesive forces dominate.

Explanation:

Adhesive forces are defined as the molecular forces which are present between different substances. For Example: When water is poured into glass, the molecular forces between the walls of container and water molecules.

Cohesive forces are defined as the molecular forces which are present between same substances.

When water is put in the glass, two types of meniscus form, one is concave meniscus and another is convex meniscus.

Concave meniscus is formed due to adhesive forces and is dominating inside the glass.

Convex meniscus is formed due to cohesive forces and is dominating on the top of glass. As, on the top of glass no walls of glass are present. So, water molecules stick together to other water molecules.

Hence, the correct answer is within the glass, adhesive forces dominate, and on top of the glass, cohesive forces dominate.