A car travels around a circular turn of radius 50 meters while maintaining a constant speed of 15 m/s.

Question

Find the minimum value for the coefficient of friction necessary to keep the car on the road.

I got .40 for the minimum value of friction.

In icy conditions, the coefficient of friction drops to 0.15. Now find the maximum safe speed for making the turn.

I got 8 m/s

Are these right?

Answer 1

centripetal force=mv^2/r

friction force=centripetal force
mg*mu= mv^2/r

mu=v^2/(rg)

b. again, friction force=centripetal force
mg*mu=mv^2/r

v^2=rg*mu
solve for v