11.If the air resistance causes a vertical retardation of 10% of value of acceleration due to gravity, then the time of flight of an oblique projectile will be decreased by nearly

12.The greatest height to which a man can throw a ball is h. What is the greatest distance to which he can throw the ball ?

13.For the same horizontal range, in how many projections can an object be projected?

14.A projectile of mass 2 kg has velocities 3 m/s and 4 m/s at two points during its flight in the uniform gravitational field of the earth. If these two velocities are perpendicular to each other, then the minimum kinetic energy of the particle during its flight is:

15.An oblique projectile has the smallest speed on its trajectory when