Question: If a car is moving at a speed of 20 m/s and the coefficient of friction between the tires and the road is 0.7, what is the maximum deceleration the car can achieve?

Options:

1. 14.7 m/s²
2. 19.6 m/s²
3. 9.81 m/s²
4. 7.0 m/s²

Correct Answer: 14.7 m/s²

Solution:

The maximum deceleration a car can achieve is given by a = μg, where g = 9.81 m/s². Thus, a = 0.7 * 9.81 m/s² ≈ 6.87 m/s².