A body is projected upward at an angle of 30degrees with the horizontal at an initial speed of 200ms-1 in how many seconds will it reach the ground? How far from the point of projection will it strike?
the upward speed is
v = 200 sin30° - 10t = 100-10t
so v=0 at t=10
That is the top of the arc, so time to land is twice that, or 20s
The horizontal speed is a constant
v = 200 cos30°
and distance = speed * time