In longitudinal vehicle (car) dynamics, which of the following force is insignificant external longitudinal force acting on the vehicle?

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BHEL Engineer Trainee Mechanical 24 Aug 2023 Official Paper

Answer 1

Explanation:

Longitudinal Vehicle Dynamics

Longitudinal vehicle dynamics refers to the study of forces and motions that occur along the direction of travel of a vehicle. This includes forces that affect the acceleration, deceleration, and overall stability of the vehicle as it moves forward or backward.
In the context of longitudinal vehicle dynamics, the buoyancy force is considered an insignificant external longitudinal force acting on the vehicle. Buoyancy force primarily relates to the force exerted by a fluid (like water) on an object submerged in it, causing the object to float or rise. Since typical vehicles (cars) operate on solid ground rather than in a fluid medium, the buoyancy force has minimal to no effect on their longitudinal dynamics.
For a vehicle, the primary forces affecting its longitudinal motion include the longitudinal tire forces, aerodynamic drag force, and rolling resistance due to tires. The buoyancy force, however, is not a significant factor in this scenario.

Additional Information Longitudinal tire force

Longitudinal tire force is a significant force in vehicle dynamics. It is the force generated by the interaction between the tires and the road surface, allowing the vehicle to accelerate, decelerate, and maintain traction. This force is crucial for the vehicle's ability to move forward or backward and is directly related to the performance and safety of the vehicle.

Aerodynamic drag force

Aerodynamic drag force is another significant factor in longitudinal vehicle dynamics. This force opposes the motion of the vehicle as it moves through the air. It depends on the vehicle's shape, speed, and surface roughness. Reducing aerodynamic drag is essential for improving fuel efficiency and achieving higher speeds.

Rolling resistance due to tires

Rolling resistance due to tires is also a critical force in longitudinal vehicle dynamics. It is the resistance that occurs when the tires roll over the road surface. This resistance is influenced by the tire material, tire pressure, road surface, and vehicle load. Minimizing rolling resistance is important for enhancing fuel efficiency and vehicle performance.