Final answer:
As the car is moving at a constant speed with no change in motion, the net force required by the engine is effectively zero, indicating that it should only counterbalance the resistive forces such as drag and rolling resistance.
Step-by-step explanation:
If a car has a mass of 1000kg and is traveling at a constant speed of 10 m/s, the force required by the engine to maintain the same speed must be enough to counteract any opposing forces such as air resistance and rolling resistance (friction between the tires and the road). In physics, this is often referred to as the 'dynamics of uniform circular motion' or 'steady-state driving conditions' where the net force on the vehicle is zero.
Since the car is moving at a constant speed, according to Newton's first law of motion (also known as the law of inertia), an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. This implies that if the car is moving at a constant speed on a level surface, the net force acting on it is zero. Hence, the engine just needs to exert a force sufficient to overcome the various resistive forces acting on the car. Without any additional information provided about these resistive forces, one can consider that no additional force is necessary beyond what is needed to address these resistances.
Therefore, without specific values for these resistive forces (drag and friction), we cannot calculate the exact force but can say that it must equal the sum of the resistive forces acting against the car's motion.