A city planner is working on the redesign of a hilly portion of the road. An important consideration is how steep the road can be so that even a low-powered car can get up the hill without slowing down. A particular small car with a mass of 1368 kg can accelerate on a flat level road from rest to 28.2 m/s in 16.3 seconds. Using this data, calculate the maximum steepness of the hill.