# Circular Motion of a Car: Finding Friction Coefficient

• vitesse86
In summary, the conversation discusses the problem of finding the static friction coefficient for a car to make a turn at 60 km/h on a flat curve. The relevant equations and known stats are provided, and the discussion centers on applying Newton's 2nd law and the equation Fcentripetal = m*(v^2/r) to find the appropriate coefficient. The conversation ends with clarification on the calculations and a request for further guidance.

## Homework Statement

I have a general question about circular motion of a car on a flat curve.
What must the static friction koefficient be if the car can make the swing by 60km/h?

Thank you,

## Homework Equations

- We have to follow Newtons 2nd law.

- Fcentripetal = m*(v^2/r)

known stats:
r= 150m
v= 16,67m/s
g= 9,81

## The Attempt at a Solution

mg = v2/r /g

m= v2/r*g

m= ((16,67*16,67)/(150*9,81))

m= 0.189

Need probably help here, not sure if I did do the equations right.

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Surely they must also have given you the radius of the track?

Have you any idea how to start the problem?

H_man said:
Surely they must also have given you the radius of the track?

Have you any idea how to start the problem?

Hi,

Thanks,

Can someone help me please, need help as soon as possible.

, thanks!

vitesse86 said:

## Homework Statement

I have a general question about circular motion of a car on a flat curve.
What must the static friction koefficient be if the car can make the swing by 60km/h?

Thank you,

## The Attempt at a Solution

So, frictional force equals to centripetal force, and also equals to that coefficient times normal force.

Find centripetal, and thus that's the frictional force (it's keeping the car in that circle)
and then
Fn.coefficient = Centripetal force
mass cancels out..
and
so
g.coefficient = centripetal acc..

hoping this would help

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harmeet_angel said:
So, frictional force equals to centripetal force, and also equals to that coefficient times normal force.

Find centripetal, and thus that's the frictional force (it's keeping the car in that circle)
and then
Fn.coefficient = Centripetal force
mass cancels out..
and
so
g.coefficient = centripetal acc..

hoping this would help

Hi,
thanks for the help.
But can't you help me a little closer, I am pretty new to this and I am also a newbee.

Thanks,

Centripetal = v^2/r
v=60 km/hr -- convert this is m/s
r=150 m

sounds like a weird answer.. perhaps me wrong

harmeet_angel said:
Centripetal = v^2/r
v=60 km/hr -- convert this is m/s
r=150 m

sounds like a weird answer.. perhaps me wrong

Can somebody help us here, please honestly!

harmeet_angel said:

Thats it, just make sure you convert units and then divide by g

turdferguson said:
Thats it, just make sure you convert units and then divide by g

My english are abit bad, can you please write down for me how to do this?

use this as a helping figure.

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hmm.. ite

so,
v=16.67 m/s
r=150 m
g= 9.81

harmeet_angel said:
hmm.. ite

so,
v=16.67 m/s
r=150 m
g= 9.81

Can you show me the calculations how u did come
to (v^2/(r.g)) ?

Sorry I am a very newbee, and need everything in with a big fork:grumpy:

vitesse86 said:
Can you show me the calculations how u did come
to (v^2/(r.g)) ?

Since this is a homework question, no one will calculate the answer for you. In fact, harmeet has given you lots of help, considering the fact that you have done nothing yet.

How about filling in numbers 2 and 3 in the homework posting template. What do you know? e.g. Do you know the equation to calculate centripetal force?

cristo said:
Since this is a homework question, no one will calculate the answer for you. In fact, harmeet has given you lots of help, considering the fact that you have done nothing yet.

How about filling in numbers 2 and 3 in the homework posting template. What do you know? e.g. Do you know the equation to calculate centripetal force?

You are right.

There, i did filling in, and did an attempt.

Was it right or?

thanks for any help,

## 1. What is circular motion and how does it apply to a car?

Circular motion is the movement of an object along a circular path. In the case of a car, it refers to the motion of the car around a curved turn or corner. This type of motion is important to understand because it affects the car's overall stability and performance.

## 2. What is the friction coefficient and why is it important in circular motion?

The friction coefficient is a measure of how much friction exists between two surfaces in contact. In the case of a car's circular motion, it is important because it determines how much friction is present between the car's tires and the road surface. This, in turn, affects the car's ability to make the turn safely and efficiently.

## 3. How do you calculate the friction coefficient for a car's circular motion?

The friction coefficient can be calculated by dividing the force of friction by the normal force. The force of friction is the force that opposes the car's motion, and the normal force is the force exerted by the road surface on the car's tires. These values can be measured or estimated using various methods, such as using a force meter or analyzing the car's acceleration and velocity.

## 4. What factors can affect the friction coefficient in a car's circular motion?

Several factors can affect the friction coefficient in a car's circular motion, including the type and condition of the tires, the road surface, the speed of the car, and the weight distribution of the car. Other factors, such as weather conditions and the incline of the road, can also play a role in determining the friction coefficient.

## 5. How can the friction coefficient be optimized for a car's circular motion?

The friction coefficient can be optimized by ensuring that the car's tires are in good condition and properly inflated, choosing a road surface with a suitable level of grip, and adjusting the car's speed and weight distribution accordingly. Additionally, understanding the relationship between the friction coefficient and the car's motion can help drivers make adjustments to improve the car's performance in circular motion.