英语翻译
calculate the magnitude of the resultant of a pair of 100km/h velocity vectors that are at right angles to each other.
calculate the speed of raindrops hitting your face when they fall vertically at3m/s while running horizontally at 4m/s.
Christopher can paddle a canoe in still water at 8km/h.How successful will he be at canoeing upstream in a river that flows at 8km/h?