船隻能否立即剎掣?

不能...如果要將船剎停....就要有一個方向相反既力...
力既定義係F(力)=m(質量).a(加速度) .....其中a可以換成
(mv-mu)/t 所以t(時間)小，力就大。
如果要立即剎停船的話....即係t=0 ......力會冇限大....所以理論上係唔得既。

Any moving object must follow the laws of mechanics. As such, a ship with a certain velocity needs a distance to stop completely eventhough its decceleration can be greatly achieved using reverse propellent.