You are driving your car with a manual transmission down a 6% grade and notice that when your foot is off the throttle, it holds at a steady speed of 115 km/hour. The vehicle conditions are:
Vehicle Mass: 1600 Kg
Frontal Area: 1.75 m^2
Aero Dynamic Drag coefficient: 0.33
Transmission ratio: 0.89
Final drive ratio: 3.55
Tire Radius: 290 mm
Rolling Resistance Coefficient: 0.015
Drive line efficiency: 100%
What is the aerodynamic drag force acting on the car at this speed?
What is the rolling resistance?
What is the engine speed?
How much drag torque must be produced by the engine to hold it at this speed?