11.For a given velocity of projection from a point on the inclined plane, the maximum range down the place is three times the maximum range up the incline. Then, the angle of inclination of the incline is:

12.A stone is projected upwards and it returns to ground on a parabolic path. Which of the following remains constant?

13.Which of the following does not affect the maximum height attained by the projectile?

14.A projectile is thrown with velocity v making an angle q with the horizontal. It just crosses the tops of two poles,each of height h, after 1 second and 3 second respectively maximum height attained by the projectile is

15.A piece of marble is projected from earths surface with velocity of 50 m/s. 2 s later, it just clears a wall 5 m high. What is the angle of projection?