Question

What is running resistance of the vehicle?

(a) Rolling resistance

(b) Aerodynamic resistance

(c) Sum of rolling and aerodynamic resistance

(d) Traction force

I had been asked this question in an online interview.

This intriguing question originated from Vehicles and Powertrain in chapter Emission Control Methods, Electric & Conventional Vehicles of Automobile Engineering

Answer 1

Correct option is (c) Sum of rolling and aerodynamic resistance

The explanation is: Running resistance is the sum of rolling and aerodynamic resistance. Frunning = Frolling + F aerodynamic = (μk * mvehicle * g) + (0.5 * ρ * Cdrag * Afront * V^2). It is the resistance that will affect when the vehicle is running. Running resistance is directly proportional to the mass of the vehicle, frontal area, and velocity. Increasing any of the above parameters will increase running resistance. Tractive force is the effort from the powertrain. Rolling resistance is the frictional resistance that wheels have to overcome. Aerodynamic resistance is the drag force acting against the motion of the vehicle.