"A projectile thrown from a point P moves in such a way that its distance from P is always increasing. Find the maximum angle above the horizontal with which the projectile could have been thrown. Ignore air resistance".

Normal to the earth, surface with the escape velocity.

Explanation:

When a projectile thrown from a point P moves in such a way that its distance from P is always increasing only means that the projectile is thrown with the escape velocity and perpendicular to the surface of the earth.Any substance when thrown with the escape velocity never returns back and its distance always increases from the earth and leaves the gravitational field of the earth.

The value of Escape velocity:

normal to the earth surface.