A projectile is projected with velocity of 40 m/s at an angle θ with the horizontal. If R be the horizontal range covered by the projectile and after t seconds, its inclination with horizontal becomes zero, then the value of cot(θ) is: [Take g = 10 m/s2]

Two projectiles A and B are launched with the same initial speed at projection angles of 15° and 30° respectively. Find the ratio of the horizontal range of A to the horizontal range of B.

If bullets are fired in all possible horizontal directions from the same point with an equal velocity of 10 m s-1 and an angle of projection of 45°, then the maximum area covered by the bullets on the ground is nearly (Take acceleration due to gravity g = 10 m s-2):