The line on the earth's surface joining the points where the field is horizontal is

An object is projected from the earth's surface with escape velocity at 30^(@) with horizontal. What is the angle made by the velocity with horizontal when the object reaches a height 2R from the earth's surface ? R is the radius of the earth. Horizontal can be considered as a line parallel to the tangent at the earth's surface just below the object .

An object is projected from the earth's surface with escape velocity at 30^(@) with horizontal. What is the angle made by the velocity with horizontal when the object reaches a height 2R from the earth's surface ? R is the radius of the earth. Horizontal can be considered as a line parallel to the tangent at the earth's surface just below the object .

Two electric +q and +4q are placed at a distance 6a apart on a horizontal plane. Find the position of the point on the line joining the two charges where the electric field is zero.

Two bar magnets are placed on a horizontal surface. Draw magnetic lines around them. Mark the position of any neutral points (points where there is no resultant magnetic field) on your diagram.