Final answer:
Total horizontal force = 92,940 N
Step-by-step explanation:
To estimate the total horizontal force opposing the motion of the car, we need to consider the drag force and the force of friction. At a constant speed, the drag force equals the power developed by the engine divided by the velocity of the car. Therefore, the drag force can be calculated as:
Drag force = Power / Velocity
The power developed by the engine is given as 90 kW, and the velocity of the car is 100 km/h. Converting the velocity to m/s:
100 km/h = 100,000 m/3600 s = 27.78 m/s
Substituting these values into the equation, we get:
Drag force = 90,000 N
Now, to estimate the force of friction, we need to know the coefficient of friction between the tires of the car and the road surface. With this information, we can use the equation:
Force of friction = Weight of the car x Coefficient of friction
Assuming the coefficient of friction is 0.3 and the weight of the car is 1000 kg x 9.8 m/s²:
Force of friction = 2940 N
Adding the drag force and the force of friction together, we can estimate the total horizontal force opposing the motion of the car:
Total horizontal force = Drag force + Force of friction = 90,000 N + 2940 N = 92,940 N