Question

the velocity of projection of a projectile is 5i+10j find time of flight

Answer 1

Ans is given in photograph attached

Answer 2

Time of flight only depends on Perpendicular velocity or velocity along the net acceleration. Here the only acceleration is g downwards . and the perpendicular velocity is 10j . So time of flight by formula = 2u/g = 2*10/10 = 2 sec