Question

On an icy winter day, the coefficient of friction between the tires of a car and a roadway is reduced to 1/5 its value on a dry day. As a result, the maximum speed vmax dry at which the car can safely negotiate a curve of radius R is reduced. The new value for this speed is what percentage of its value on a dry day?

Answer 1

The force of friction is 1/5 of what it was, so you can only have 1/5 the centripetal acceleration. \[a_c=v^2/r\]r stays the same, so your v is\[\sqrt{1/5}\]times what it was before. Therefore 44.7% of the speed on a dry day