play phryzby with physics

Q. A truck starts from rest and accelerates uniformly at 2.0 m/s². At t = 10 s, a stone is dropped by a person standing on the top of the truck (6 m high from the ground). Neglect air resistance, and take g as 10 m/s². At what angle to the horizontal is the stone moving at t = 11 s, in degrees? expects -26.6°