Solving Kinetic Friction: Find Coefficient of Friction from Car Stop

Click For Summary
SUMMARY

The discussion focuses on calculating the coefficient of kinetic friction (uk) for a car that stops after traveling 40 meters from an initial speed of 20 m/s. The user applies the equation for acceleration, deriving it as 5 m/s² using the formula (final velocity² - initial velocity²) = 2 * a * distance. Subsequently, the user balances the forces to find uk by rearranging the equation to uk = a/g, resulting in a coefficient of kinetic friction of 0.5.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Familiarity with the concepts of kinetic friction and normal force
  • Ability to manipulate algebraic equations
  • Knowledge of basic physics formulas related to motion
NEXT STEPS
  • Study the derivation of the equations of motion in physics
  • Learn about the factors affecting the coefficient of friction
  • Explore real-world applications of kinetic friction in automotive safety
  • Investigate the role of tire materials in friction performance
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, as well as educators and anyone interested in understanding the principles of friction in motion.

mels
Messages
2
Reaction score
0

Homework Statement



A car is moving with a speed of 20m/s when the brakes are applied. The wheels lock (stop spinning). After traveling 40m, the car stops. Determine the coefficient of kinetic friction between the tires and the road.

Homework Equations



Fk=uk x Fn

The Attempt at a Solution



I don't know how to encorporate the given into the equation !
 
Physics news on Phys.org
There's another equation you need, one that puts all the given data together.
 
You can apply simple formula...

calculate the acceleration 'a'... by
(square of final velocity)-(square of initial velocity)=2x a x distance

a=20x20/(2x40)
a=5

balance the force
uk x mass x g = mass x a
uk=a/g
uk=5/10=0.5
 
Last edited by a moderator:
okay thank you ! i really appreciate it :)
 

Similar threads

Replies
18
Views
3K
  • · Replies 16 ·
Replies
16
Views
6K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 36 ·
2
Replies
36
Views
4K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 3 ·
Replies
3
Views
22K
  • · Replies 12 ·
Replies
12
Views
4K