More help finding frictional force.

  • #1
I really am not getting this physics stuff...again I thought I had this one figured out but it doesn't seem to be right.
So the question...
A 49.2 kg car is moving at 12.6 m/s around a horizontal curve whose radius is 31.3 m. What is the magnitude of the fictional force required to keep the car from sliding?

and this is what I did..
I found my net force for x and y
Fy = may
Fy = 0
N- W = 0
N = mg

Fx = max
fs = max
u x N = m(v^2/r)

so then I substituted in my N and got
u x mg = m(v^2/r)

and I solved for u (frictional force...I'm just using u for the term)

u x (49.2kg)(9.81m/s^2) = (49.2kg)(12.6^2/31.3m)

and it works out to be 0.517 and the computer is telling me I'm wrong once again. so I must be wrong.
 

Answers and Replies

  • #2
OlderDan
Science Advisor
Homework Helper
3,021
2
The question does not ask you to find μ. It asks you for the frictional force.
 
  • #3
Thank you! I have some serious problems with reading these things wrong.
 

Related Threads on More help finding frictional force.

  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
2
Views
983
  • Last Post
Replies
0
Views
2K
  • Last Post
Replies
3
Views
4K
Replies
11
Views
4K
  • Last Post
Replies
11
Views
1K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
3
Views
1K
Replies
3
Views
2K
Replies
4
Views
2K
Top