試題詳解

4. If the evaporation of the droplet is considered, obviously, the small droplets would evaporate first before falling on the ground. However, the evidence demonstrates that large droplets are not affected by evaporation. Please calculate the minimum size (in diamcter) of the droplet before it falls on the groud. Assume the initial horizontal velocity of the droplet is 2 m/s and the initial height of the droplet is set as 1.5 m. The transmission distance is 2 m.
(A) 134 um,
(B) 226 um,
(C) 474 um,
(D) 508 um,
(E) 668 um