Question

skid marks about 6.7 km long. If the car had an initial speed of 425 km/h, estimate the coefficient of kinetic friction. The acceleration of gravity is 9.81 m/s 2 .

Answer 1

Explanation: F=umg where u is coefficient of kinetic friction.

But F=ma.

a = u^2/2S

U= 425km/hr = (425*1000)/3600 =118m/s

S= 6.7km = 6700m

a = 118*118/ (2*6700) = 1.04m/s

u = 1.04/9.8 =0.11