Posted by engmath on .
A car traveling on a flat (unbanked) circular track accelerates uniformly from rest with a tangential acceleration of 1.70 m/s2.The car makes it one quarter of the way around the circle before it skids off the track. Determine the coefficient of static friction between the car and track from these data.
I thought the answer was 0.5449 but its wrong. no matter what I do i keep getting the same answer!

Physics 
bobpursley,
Why would you think the answer is .5446? I will be happy to critique your work

Physics 
bobpursley,
you need to round off to three sig digits

Physics 
engmath,
α=a/r
the time it takes to travel π/2 radians is
related by
π/2=.5*a*t^2/r
solve for t
t=sqrt(π*r/a)
ω=α*t
Plug in t and a/r
ω=sqrt(a*π/r)
The force is m*ω^2*r
F=m*a*π
friction is
m*g*µs
then
m*g*µs=m*a*π
so basically....
µs=a*π/g
=1.70pi/9.8= 0.54497 ====> sig figs 0.545 
Physics 
engmath,
and that answer comes up as incorrect...

Physics 
Nurik,
From which book this tasks?