[填空题]
A projectile is launched from grour.+8vzbhn u u)nd level to the top,.leq.g(qgr3cg( lv n of a cliff which is 195 m away and 155 m hig.q qg3cr. g(gl,nl ve(h (see
Fig. 3-47). If the projectile lands on top of the cliff 7.6 s after it is fired, find the initial velocity of the projectile (magnitude and direction). Neglect air resistance.