Here's why:
* Net Force: The key is that the forces acting on the object must balance each other out. This means the net force (the overall sum of all the forces) acting on the object is zero.
* Newton's First Law: Newton's First Law of Motion states that an object at rest stays at rest, and an object in motion stays in motion at a constant speed and direction *unless acted upon by a net force*.
* Examples:
* A book sitting on a table: Gravity pulls the book down, but the table pushes back with an equal and opposite force, keeping the book stationary.
* A person standing still: Gravity pulls them down, but the ground pushes back with an equal force.
* An airplane flying at a constant speed and altitude: The thrust from the engines balances the drag from the air, and the lift from the wings balances the force of gravity.
In short, an object can experience multiple forces and still remain at rest or move with constant velocity if the forces cancel each other out, resulting in a net force of zero.
