Question

A car skids to a stop on a horizontal surface. The speed of the car goes down by 6.0 m/s each second as it is skidding. What is the coefficient of the friction between the tires and the road?

• A. 0.61
• B. 0.52
• C. 0.3
• D. 1.63
• E. 0.98

Answer 1

Answer: (A)

0.61

Retardation of the car due to friction $|a|=6.0$ $m/s^2$

Retardation $|a|=\frac{f}{m}=\frac{\mu mg}{m}=\mu g$ where $\mu$ is the coefficient of friction

$\therefore$ $6.0=\mu \times 9.8$ $⟹\mu =0.61$