Engineering Mechanics Practice Exam

Rolling resistance is the small opposing force that a tire experiences as it deforms and recovers while rolling on a surface. For ordinary car tires on concrete, this resistance is relatively modest because the tire’s deformation losses are moderate on a hard, smooth surface. The coefficient describing this rolling resistance typically lies around 0.01 to 0.02; the range 0.01 to 0.015 fits right in this practical band and reflects common tires and concrete conditions. In practice, the resisting force is F = Crr × N, where N is the normal load; for a typical car, this yields a few hundred newtons of resistance, which aligns with real-world drivetrain requirements and fuel efficiency. Values much higher would imply unrealistically large losses for smooth concrete, while values far lower would underestimate the energy lost to tire deformation.