有關terminal velocity一問

air resistance = bv

where b is a constant that depends on the properties of the fluid and the dimensions of the object, and v is the velocity of the object.

hence, eventually the terminal velocity would come and the weight would be balanced by the air resistance such that bv = mg

if u use 較細ge傘, then the constant " b " would be smaller so that the terminal velocity would be larger to equilibrate air resistance with the weight

如果用較細的傘子, 理論上而要較長時間去 balance 個下墜力(mg)
由於v=u+gt, 在同一個加速度, t愈長, v會愈大...所以terminal velocity會比大傘高

至於去唔去得到terminal velocity...就要睇起跌高度...太矮的話
可能未到terminal velocity已經"掂"到地面lu