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Difficulty: HardBalance and Center of Gravity

Commercial vehicles hauling top-heavy cargo with an elevated center of gravity will consistently skid sideways before tipping over in a sharp turn, providing a physical warning before a rollover occurs.

Answer: Answer

Answer

False. Vehicles with a high center of gravity can roll over abruptly without any prior tire skidding or loss of traction.
The statement is false because an elevated center of gravity drastically lowers a commercial vehicle's roll-stability threshold. On standard paved surfaces, tire adhesion is strong enough that centrifugal force will cause a top-heavy vehicle to tip over well before the tires reach their traction limit and skid. Consequently, rollovers regularly occur without any preliminary skidding or handling feedback.

Step-by-Step Solution

1
Evaluate how cargo placement height influences a commercial vehicle's composite center of gravity and lateral roll stability.
Stacking dense freight high elevates the center of gravity, which creates a large tipping moment during cornering maneuvers.
The roll stability of a commercial motor vehicle is inversely proportional to the height of its payload's center of mass.
2
Compare the lateral acceleration required to initiate a rollover against the lateral force required to induce tire sliding on standard roadway surfaces.
Tire-pavement friction on dry pavement is generally high (0.70.7 to 0.8 g0.8\text{ g}), whereas a top-heavy combination vehicle may roll over at lateral acceleration levels as low as 0.250.25 to 0.35 g0.35\text{ g}.
When the rollover threshold is lower than the coefficient of friction, tipping occurs before sliding.
3
Determine whether tire skidding provides a preliminary warning of an impending rollover.
Because the vehicle tips before the tires lose adhesion, rollover occurs without any preliminary skidding warning.
Drivers cannot rely on tire slip as a safety buffer when operating top-heavy commercial vehicles.

Key Concept

Center of Gravity and Rollover Threshold Dynamics
Estimated Time:1m 0s
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Topics

Balance and Center of Gravity

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