# Finding the coefficient of friction

• return42
In summary, the conversation discusses a race-car driver's discovery of their maximum acceleration without spinning their tires and the question of finding the coefficient of friction between the tires and the road. The attempt at a solution involves using Newton's second law and leads to a value of 0.41 for the coefficient of friction, but the answer provided in the book differs. It is determined that this is due to the tires experiencing static friction up to the point of slipping.
return42

## Homework Statement

A race-car driver discovers that he can accelerate at 4.0 m/s2 without spinning his tires, but if he tries to accelerate more rapidly, he always "burns rubber." What is the coefficient of friction between his tires and the road?

0.62

## Homework Equations

Kinetic friction force = ukN
Static friction force <= usN

## The Attempt at a Solution

I'm really lost with this one. I tried starting with Newton's second law and end up at:
ukmg = ma
ukg = a
uk = a/g = 0.41

Which is not the answer behind the book. Is this considered static friction? I'd think not because the tires are slipping relative to the ground. Anyone can put me on the right path?

It is static friction up to the point where the tires start to slip. So I get u_s = 0.41. I don't understand the given answer, unless some info is missing.

## What is the coefficient of friction?

The coefficient of friction is a measure of the amount of resistance between two surfaces when they are in contact with each other. It is a dimensionless quantity that ranges from 0 (no friction) to 1 (high friction).

## How is the coefficient of friction calculated?

The coefficient of friction is calculated by dividing the force required to move an object over a surface by the weight of the object. This calculation can be done using a friction force sensor and a scale.

## What factors affect the coefficient of friction?

The coefficient of friction can be affected by several factors such as the nature of the surfaces in contact, the roughness of the surfaces, the temperature, and the presence of any lubricants.

## Why is it important to find the coefficient of friction?

Finding the coefficient of friction is important in understanding the behavior of objects in motion. It is also crucial in designing and optimizing machines and structures to reduce friction and improve efficiency.

## How can the coefficient of friction be reduced?

The coefficient of friction can be reduced by using lubricants, polishing surfaces, and choosing materials with lower coefficients of friction. Additionally, reducing the weight of objects can also decrease the friction force.

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