# What is the minimum frictional force required for a vehicle to operate smoothly, retain traction, and prevent any skids?

I am not looking for a specific number of course. I know that it may perhaps vary with different vehicles. However, I'm trying to figure out how to theoretically calculate the minimum necessary frictional force. In other words, what variables determine how much kinetic frictional force is required to maintain traction?

I am not asking for how to find frictional force, but how to know whether a vehicle can or cannot operate on certain roads with varying coefficients of kinetic friction.

I guess a main "sub-question" would be is min. friction requirement independent or dependent of mass?

In other words, do smaller vehicles which lesser mass have smaller min. friction requirements than bigger vehicles? Is it really determined by mass or rather the normal force, which can change in magnitude in an incline?

As an example, can a truck travel with sufficient traction with the same min. frictional force required for a bicycle?

Is there an equation relating mass or normal force to determine the min. frictional force required?

basically the acceptable coefficient of friction friction requirement is not dependant on mass because the heavier the vehicle is the harder in presses on the road, and so the more it grips.

This is what all types and sizes of road vehicles use rubber tyres.

how much actual friction is required depend on what is being done, an accelerating vehicle needs to provide the acceleration through the force the tyres put into the road, while one traveling in a straght line on a flat sufrace needs to only compensate for drag.

Can a truck travel with sufficient traction with the same min. frictional force required for a bicycle?

only if the car has the same mass as the bicycle, or possibly if the car performs much less extreme manouvers. insufficient friction is what allows skids.

• Thank you! So acceptable coefficient of kinetic friction is actually what decides whether any object, regardless of its mass, can be driven without skidding? If the acceptable coefficient is not mass dependent, how is it calculated mathematically? For instance, how do we know without trial and error that a car cannot run on ice but it can on asphalt?
– ARJ
Dec 30 '19 at 6:14
• The coeficient of friction will tell you how much acceleration is possible in g (assuming a flat level surface) after the simulations are completed, real cars are test driven. Dec 31 '19 at 21:40