Final answer:
The total frictional force acting on the car can be calculated using the power developed by the engine and the speed of the car. The power developed in the engine is 60.0 hp, which is equivalent to 44742 W. Substituting the values, the total frictional force acting on the car at 55 mph (24.6 m/s) is 1820 N.
Step-by-step explanation:
When an automobile moves with a constant velocity, the power developed in the engine is used to overcome the frictional forces exerted by the air and the road. The total frictional force acting on the car can be calculated using the power developed by the engine and the speed of the car.
The power developed in the engine is given as 60.0 hp. To convert this to watts, we use the conversion factor 1 hp = 745.7 W. So, the power developed in the engine is 60.0 hp × 745.7 W/hp = 44742 W.
The total frictional force acting on the car can be calculated using the formula:
Frictional force = Power developed in the engine / Velocity of the car
Substituting the values, we get:
Frictional force = 44742 W / 24.6 m/s = 1820 N
Therefore, the total frictional force acting on the car at 55 mph (24.6 m/s) is 1820 N