Mathematics · Projectile Motion

A small ball is projected from (0 m, 0 m) in the x-y plane at t = 0 s. Its velocity vec v (in m/s) at t = 2 s is vec v = 40î + 10ĵ. Here î and ĵ are unit vectors along the x-axis and y-axis respectively. The total time of flight of the ball is: (take g = 10 m/s2)