84. 4 relative velocity addition and accelerations Exercise 1 a train travels due south at 28 m/s(relative to the ground in a rain that is blown to the south by the wind. The path of each raindrop makes an angle of 64 with the vertical, as measured by an observer stationary on the earth. An observer on the train however. see perfectly vertical tracks of rain on the windowpane. Determine the speed of the rain drops relative to the ground 84. 4 relative velocity addition and accelerations Solution: =v+卩 g From the problem, we have vsin64°=p,=28m/s 28 33.3m/s sin64°0.8410 Exercise 1: A train travels due south at 28 m/s(relative to the ground) in a rain that is blown to the south by the wind. The path of each raindrop makes an angle of 64°with the vertical, as measured by an observer stationary on the earth. An observer on the train, however, see perfectly vertical tracks of rain on the windowpane. Determine the speed of the rain drops relative to the ground. §4.4 relative velocity addition and accelerations Solution: rt v r tg v r rg v r tg v r o 64 o 64 rg v r rt v r From the problem, we have sin64 = = 28m/s rg tg v v o 33.3m/s 0.84 28 sin64 = = = o tg rg v v §4.4 relative velocity addition and accelerations rg rt tg v v v r r r = +