Max Angle for Parking on Steep Hill: Coefficient of Friction Calculation

  • Thread starter dabouncerx24
  • Start date
HIn summary, the maximum angle at which a car can be parked on a hill depends on the coefficient of friction between hard rubber and normal street pavement. To find this angle, one can perform a forces analysis and set the friction force equal to the component of the force of gravity. This can be solved for the angle theta, which will be the maximum angle at which the car can be parked without sliding down the hill. In addition, the deceleration of a car on an inclined road can be found by applying the same parameters used for a level road and solving for the new deceleration. This can be done using the sigma F equation and understanding the concept of skidding.
  • #1
dabouncerx24
11
0
The coefficient of friction between hard rubber and normal street pavement is about 0.8. On how steep a hill (max angle) can you leave a car parked?


I have no idea how to do it since it doesn't give you the weight or anything.
 
Physics news on Phys.org
  • #2
Let's see, so why don't you assign the car a mass m, and then start doing the forces analysis, and see what will be the force of friction be, and you know the force of gravity (a component of it) will be the force making the car fall, so if the friction force equals that force they will cancel and the car won't fall, then you can find the angle for that case.
 
  • #3
Forces analysis..meaning the Friction Force = Ums + Fn equation??
The component of force of gravity will simply be Fwsin? right.


I am so bad in physics...
 
  • #4
Well on

y-axis:

[tex] N = mgcos\theta [/tex]

on x-axis:

If there's not movement
[tex] -mgsin\theta + \mu_{s}mgcos\theta = 0 [/tex]

if

[tex] \mu_{s}mgcos\theta = mgsin\theta [/tex]

Then the block should be at equilibrium, and the angle theta should be the max angle.

solve for theta (i simplifyed for you, and remember your trigonometry)

[tex] \mu_{s}cos\theta = sin\theta [/tex]
 
  • #5
thank you very much
 
  • #6
Welcome to PF!, it was a pleasure to be of assistance, also don't discourage yourself on physics, the universe we live is a very interesting place, where many theories tries to explain how it works. Just imagine the problems, understand the concepts... and you should do ok :smile:
 
  • #7
I'm sure I will get better as time progress, thank you for the warm welcome for I am sure I will be coming here A LOT during the school year.

Well...another problem already.

A car can decelerate at -5.10 m/s^2 w/o skidding when coming to rest on a level road. What would its deceleration be if the road were inclined at 12 degrees upward.

I'm guessing the sigma F equation comes into play here...? Thats all I know... :frown:
 
Last edited:
  • #8
i'm sorry, I'm spanish what's skidding?
 
  • #9
Cyclovenom,
skidding means sliding on a surface ...

dabouncer,
for the first case of level road,
what parameters can u find out ? (note : the car comes to rest)
whatever parameters u find for this case , apply it to second case and find its deceleration? ...

-- AI
 

1. What kind of problem do you need help with?

As a scientist, I work on a variety of problems related to my field of study. Please provide more context or details about the specific problem you need help with so I can better assist you.

2. Can you provide any background information on the problem?

Understanding the background and context of a problem is crucial in finding a solution. Please provide any relevant information or data that you have on the problem so I can have a better understanding of the situation.

3. How urgent is the problem?

Some problems may require immediate attention, while others can be addressed over a longer period of time. Please let me know the urgency of the problem so I can prioritize and allocate my resources accordingly.

4. What have you tried so far to solve the problem?

It's always helpful to know what steps have been taken so far in attempting to solve a problem. This can prevent repeating unsuccessful methods and give me an idea of where to start in finding a solution.

5. Is there any specific area or aspect of the problem that you need help with?

Some problems may have multiple components or aspects to them. Please let me know if there is a specific area or aspect of the problem that you need help with so I can focus my efforts and provide more targeted assistance.

Similar threads

  • Introductory Physics Homework Help
Replies
5
Views
5K
Replies
10
Views
766
  • Introductory Physics Homework Help
Replies
2
Views
12K
  • Introductory Physics Homework Help
Replies
3
Views
2K
Replies
4
Views
966
  • Introductory Physics Homework Help
Replies
6
Views
6K
  • Introductory Physics Homework Help
Replies
20
Views
2K
  • Introductory Physics Homework Help
2
Replies
48
Views
6K
  • Introductory Physics Homework Help
Replies
5
Views
6K
  • Introductory Physics Homework Help
Replies
5
Views
2K
Back
Top