Question

A car moves around a curve whose radius is 320m. The car's speed is 28m/s. What is the coefficient of static friction between the road and the tires? Oh and the centripetal force is 2.45m/s/s

Answer 1

So the equation for centripetal force has the same units as acceleration,

\[a_c=\frac{ v^2 }{ r }\]

Now the formulas for force are:

F=ma and F=un

where u is the coefficient of static friction and n is the normal force.

Now we can brew these altogether and see that the forces are in equilibrium:

\[m \frac{ v^2 }{ r }=umg\]

And hey, what do you know, we can solve for u without actually knowing the mass of the car!