A boy playing on the roof of a 10m high building throws a ball with a speed of 10 m/s at an angle of 30° with the horizontal. How far from the throwing point will the ball be at the height of 10 m from the ground (g = 10 m/s2, sin 30° = 1/2, COS 30° = √3/2)
(a) 8.66 m
(b) 5.20 m
(c) 4.33 m
(d) 2.60 m
