Question

A boy playing on the roof of a 10 m high building throws a ball with a speed of 10 m/* 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/* , sin30° = 1/2, cos30° = √3/2 ]

(a) 5.20 m

(b) 4.33 m

(c) 2.60 m

(d) 8.66 m

Answer 1

Correct option (d) 8.66 m
Explanation :

The ball will be at point P when it is at a height of 10 m from the ground. So, we have to find the distance OP, which can be calculated directly by considering it as a projectile on a levelled plane (ox).