Answer to Question #107774 in Physics for fatima

Question

7. A 1000-kg car rounds a curve on a flat road of radius 50 m at a speed of 15 m/s (54 km/h). Will the car follow the curve, or will it skid? Assume:

(a) the pavement is dry and the coefficient of static friction is
μs = 0.60.



(b) the pavement is icy and μs = 0.25. (2 mark)

Answer 1

The Newton's second law says

$$ma=F.$$

For the circular motion on the flat road

$$m\frac{v^2}{R}=\mu_smg.$$

Hence, the car will follow the curve if

$$\mu_s\geq\frac{v^2}{gR}=\frac{15^2}{9.8\times 50}=0.46$$

(a)

$$\mu_s=0.60\geq 0.46$$

The car will follow the curve.

(b)

$$\mu_s=0.25\leq 0.46$$

The car will skid the curve.