# Is my driving efficient?

**Classical Mechanics**Level 3

Cindy is driving her Camry at 36 km/h on a straight road, when she spots a traffic light turn red 75 meters ahead. She decelerates at a constant rate, and 6 seconds later she stops right at the traffic light. She waits 2 minutes for the light to turn green, and then accelerates at a steady rate of \(2\text{ m/s}^2\) until she reaches her previous speed of 36 km/h. Then she cruises at a steady speed for 2 kilometers. Approximately what is her overall fuel efficiency in kilometers per liter? Round your answer to the nearest integer.

**Details and Assumptions**

- The fuel consumption rate when decelerating or staying still at the red light is 20 ml/min.
- The fuel consumption rate when driving at a steady speed is 30 ml/min.
- The fuel consumption rate when accelerating at \(2\text{ m/s}^2\) is 1.2 ml/s.
- Ignore any air resistance.
- The given measures do not exactly represent the actual performance of a Camry.

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