A body is projected at an angle of 30° with the horizontal and with a speed of 30 ms-1. What is the angle with the horizontal after 1.5 s ? (g = 10 ms-2)

The time of flight is given byT=2usin⁡θg=2×30×1/210=3sThus, after 1.5 s, the body will be at the highest point.  So the direction of motion will be horizontal after 1.5 s, the angle with the horizontal is 0°.