Physics
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!

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

you need to round off to three sig digits

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 
and that answer comes up as incorrect...

From which book this tasks?