A projectile is thrown into space so as to have a maximum possible horizontal range of $400$ metres. Taking the point of projection as the origin, the co-ordinates of the point where the velocity of the projectile is minimum are

If at any point on the path of a projectile its velocity is $u$ at inclination $\alpha$ then it will  move at right angles to former direction after time

A projectile thrown with velocity $v$ making angle $\theta$ with vertical gains maximum height $H$ in the time for which the projectile remains in air, the time period is

When a body is thrown with a velocity $u$ making an angle $\theta $ with the horizontal plane, the maximum distance covered by it in horizontal direction is

A bullet is dropped from the same height when another bullet is fired horizontally. They will hit the ground

A body is projected with velocity $u$ making an angle $\alpha$ with the horizontal. Its velocity when it is perpendicular to the initial velocity vector $u$ is