Understanding the Concepts

* Newton's First Law: An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

* Constant Velocity: This means the car is not accelerating.

* Balanced Forces: For an object to have constant velocity, the forces acting on it must be balanced.

Solution

Since the car is moving at a constant velocity, the forces acting on it must be balanced. This means the force needed to maintain the velocity must be equal and opposite to the forces opposing the motion.

Therefore, you need a force of 800 N to maintain the velocity.

Important Note: The car's mass (1200 kg) is not directly needed to calculate the force required to maintain constant velocity. Mass is relevant when calculating acceleration, but not when the object is moving at a constant speed.