When fluid flows through a hole in a vessel, friction forces between the moving liquid and the wall of the leak convert some of the kinetic energy of the liquid into thermal energy, resulting in:

• A. An increase in fluid velocity
• B. A reduction in fluid velocity
• C. Formation of an aerosol
• D. No energy change

Answer: (C)

When liquid flows through a small hole, viscous friction between the moving fluid and the hole walls dissipates part of the fluid’s kinetic energy as heat. This loss of kinetic energy means the fluid has less energy driving its motion, so its velocity decreases as it passes through the hole. The temperature of the liquid can rise slightly due to this energy transfer, but the primary observable effect of the frictional loss is a slowdown, not an increase in speed. Aerosol formation isn’t produced by this friction alone; atomization would require strong shear forces that physically break the liquid into droplets, which isn’t implied by simple viscous heating. There is indeed an energy change, since some kinetic energy becomes thermal energy.