Question

Suppose the vehicle is running at a constant speed on the flat road with rolling resistance = 100 N and aerodynamic resistance = 100 N, what is the traction force required?

(a) 100 N

(b) 0 N

(c) 200 N

(d) 50 N

The question was posed to me in an interview for internship.

The query is from Vehicles and Powertrain topic in portion Emission Control Methods, Electric & Conventional Vehicles of Automobile Engineering

Answer 1

Correct choice is (c) 200 N

For explanation I would say: Fnet = Ftraction – Frolling – Faerodynamic – Fgradient = 0 N (constant speed). Flat road ⇒ Fgradient = 0. Hence Ftraction = Frolling + Faerodynamic + Fgradient = 100 + 100 + 0 = 200 N.