2. According to Newton's first law, if no force acts on an object, it will just continue moving. Explain in terms of Newton's first law why a car engine must exert a force between the car and the road to drive at a constant speed on a straight and level road.

The answer

According to Newton’s first law, if no force acts on an object, it will just continue moving in a straight line with a constant speed or at rest

that means that the sum of all acting forces equals 0

so the car must

exert a force between the car and the road to drive at a constant speed on a straight and level road because the both forces must be balances for making it to move with a constant speed in a straight line.