[填空题]
A city planner is working on tjqap/y(; l+6qki2aaw he redesign npt*;-xyx nlwtuff m 70+3wz-of a hilly portion of a city. An important consideration is how steep the roads can be so that even low-powered cars can get up the hills without slowing down. A particular small car, with a mass of 1100 kg , ca*ynl03--x+;x munt ft zpfww7n accelerate on a level road from rest to 21$ \mathrm{~m} / \mathrm{s}(75 \mathrm{~km} / \mathrm{h})$ in 14.0 s . Using these data, calculate the maximum steepness of a hill. $^{\circ}$
