Droplet Shape — Why Falling Water Drops Tend to Spheres Falling drops of water tend to assume a spherical shape predominantly due to which physical property of water?

Introduction:
The equilibrium shape of small liquid droplets results from a competition between interfacial forces and body forces. Understanding which property governs droplet sphericity is important in sprays, inkjet printing, and meteorology.

Given Data / Assumptions:

• Drops are small enough that surface effects dominate over gravity.
• Ambient air offers negligible viscous resistance to shape at equilibrium.
• No electric or magnetic fields acting on the droplet.

Concept / Approach:
Surface tension acts to minimize surface area for a given volume. Among all shapes with the same volume, the sphere has the minimum surface area. Therefore, in the absence of strong external forces, droplets tend toward spherical shapes due to surface tension.

Step-by-Step Solution:
Recognize that energy of the interface is E = sigma * A, where sigma is surface tension and A is area.For fixed volume, minimizing A minimizes E.A sphere provides the smallest area, hence is energetically favored.

Verification / Alternative check:
As droplet size increases, gravity distorts the shape, making it oblate; small droplets (e.g., fog, mist) remain nearly spherical—consistent with surface-tension dominance.

Why Other Options Are Wrong:
Compressibility has negligible effect on shape at normal conditions; capillarity refers to interaction with walls, not free droplets; viscosity resists flow but does not set the equilibrium shape.

Common Pitfalls:
Assuming large raindrops are spherical—larger drops flatten due to aerodynamic forces; confusing capillarity (wetting) with free-surface tension effects.

Final Answer:
surface tension of water