When accelerating, there is more friction between the tire and the road as it rolls compared to when it slides or skids. This is due to several factors:
Normal Force: When the tire rolls, the weight of the vehicle is distributed over a larger contact area between the tire and the road. This results in a greater normal force acting perpendicular to the surface of the road. The normal force plays a crucial role in determining the frictional force.
Adhesion: Rolling tires create a higher level of adhesion between the tire and the road surface. Adhesion refers to the molecular attraction between two substances in contact. The deformation and gripping of the rubber tire with the road surface enhance the adhesion, leading to an increased frictional force.
Deformation and Elasticity: Tires are designed to deform slightly when in contact with the road. This deformation allows the tire to maintain contact with the road surface over a larger area, increasing the frictional force. The elasticity of the tire also contributes to this effect by helping the tire regain its shape after deformation, maintaining continuous contact and friction.
Traction: Rolling tires provide better traction due to the combination of the factors mentioned above. The increased normal force, adhesion, and tire deformation allow for more efficient transfer of the engine's power to the road, resulting in improved acceleration.
In contrast, when a tire slides or skids, the contact area between the tire and the road decreases significantly. The reduced contact area leads to a decrease in the normal force and adhesion, resulting in less friction between the tire and the road. As a result, the sliding or skidding tire experiences less frictional force, making it more difficult to control and potentially reducing the vehicle's ability to accelerate effectively.