Falling raindrops assume a nearly spherical droplet shape due to the influence of__________________?
Show answer Hide answer
Answer: C. surface tension forces
Explanation
Surface tension forces pull falling liquid droplets into a nearly spherical shape naturally. This intermolecular contraction minimizes the total surface area of the liquid volume effectively. Cohesive forces between fluid molecules create a stretched membrane effect at the droplet boundary. Surface tension arises from the unbalanced attractive forces acting on molecules at the liquid surface. Spheres possess the minimum possible surface area for any given volume in three-dimensional space. Fluid mechanics principles dictate that droplets minimize surface energy under static equilibrium conditions.
Understanding droplet formation is critical in meteorology when studying rainfall and cloud physics phenomena. Spray painting and agricultural pesticide dispersion rely heavily on droplet breakup and surface tension. Industrial combustion systems analyze fuel droplet shapes to optimize evaporation and ignition efficiency. Viscosity describes a fluid internal resistance to shear flow rather than boundary shape forces. Air resistance flattens or distorts falling droplets slightly rather than pulling them into spheres. Atmospheric pressure acts uniformly around the droplet but does not drive the spherical geometry.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. The cohesive fluid property whereby molecules of the same substance attract each other is termed___________________?
Show answer Hide answer
Answer: B. cohesion
Cohesion is the intermolecular force that causes molecules of the same substance to stick and attract each other. This fundamental fluid property explains why water molecules bind together to form droplets and resist sep...
Q2. A proximate analysis of solid fuel determines the percentage composition of ____________________?
Show answer Hide answer
Answer: B. fixed carbon, ash, volatile matter, moisture
Proximate analysis of solid fuel determines the percentages of fixed carbon, volatile matter, moisture, and ash. Standard laboratory testing procedures for proximate analysis measure these four primary constituent fracti...
Q3. Railway track rails are conventionally manufactured from_______________?
Show answer Hide answer
Answer: C. high carbon
Railway track rails require high mechanical strength, hardness, and exceptional wear resistance during service. High carbon steel provides the necessary microstructural hardness to withstand heavy rolling wheel loads. Ca...
Q4. The recrystallization temperature of a cold-worked metal can be lowered by_________________?
Show answer Hide answer
Answer: D. all of the above
The recrystallization temperature of a cold-worked metal can be significantly lowered through material purification. Grain refinement and prior plastic deformation also increase internal stored energy, facilitating earli...
Q5. The dimensionless ratio relating fluid inertia forces to elastic forces is designated as__________________?
Show answer Hide answer
Answer: A. Mach number
Mach number is the dimensionless ratio representing the speed of a fluid relative to the speed of sound. This parameter directly relates fluid inertia forces to elastic forces within compressible aerodynamic flow fields....
Q6. A refrigerating system operates with a suction pressure of 10 kg/cm² gauge and condensing pressure of 67 kg/cm². What is the refrigerant________________?
Show answer Hide answer
Answer: B. Carbon dioxide
Carbon dioxide operating pressures are notably high, with typical suction and condensing pressures matching these values in CO2 refrigeration systems. Refrigeration cycles utilizing carbon dioxide operate at exceptionall...