Option 1: Zero acceleration always implies zero velocity. This statement is incorrect. Zero acceleration means that the velocity of the object is not changing, but it does not necessarily mean that the velocity is zero. For example, if an object is moving at a constant velocity, it has zero acceleration because its velocity is not changing.

Option 2: Zero acceleration has no relation with the velocity of the object. This statement is incorrect. Zero acceleration means that the velocity of the object is not changing. If the object is already at rest (zero velocity) and has zero acceleration, it will remain at rest. If the object is already in motion with a non-zero velocity and has zero acceleration, it will continue to move at a constant velocity.

Option 3: Zero velocity at any instant necessarily means zero acceleration at that instant. This statement is incorrect. Zero velocity at any instant does not necessarily mean zero acceleration at that instant. For example, if an object is thrown upwards, at the highest point of its trajectory it momentarily comes to rest (zero velocity), but it still experiences acceleration due to gravity.

Option 4: Acceleration is constant all throughout the free fall. This statement is correct. In free fall, when an object is only influenced by gravity, its acceleration remains constant