How far has the car gone from its start?

Question

A car starts from rest and travels for 4.9 s with a uniform acceleration of +1.2 m/s(squared). The driver then applies the brakes, causing a uniform acceleration of -2.2 m/s(squared). The breaks are applied for 1.70 s.

Answer 1

First leg it travels s1 = (a1)(t1)^2/2 = 14.406 m, reaching v1 = (a1)(t1) = 5.88 m/s.
Second leg it decelerates from v1 reaching v2 = v1 + (a2)(t2) = 2.14 m/s over a distance s2 = (v1+v2)(t2)/2 = 6.817 m.
Total distance = s1 + s2 = 21.223 m