1. Calculate the Total Power Output:

* Power per kg = 500 W/kg

* Total Power = Power per kg * Mass of engine = 500 W/kg * 150 kg = 75000 W

2. Calculate the Force:

* Power = Force * Velocity

* Force = Power / Velocity = 75000 W / 20 m/s = 3750 N

Therefore, the car engine exerts a force of 3750 Newtons.