Objects in equilibrium (ie no net forces) continue to go in the direction and speed they were already heading. Forces are only needed to change direction.
Direction is always a straight line, so to go round a corner you need to be applying a continuous force resisting going in a straight line. If you start drifting wide it means the net size of that force has reduced.
Objects in equilibrium (ie no net forces) continue to go in the direction and speed they were already heading. Forces are only needed to change direction.