A motorcycle ride consists of two segments, as shown in the figure blow. During segment 1, the motorcycle starts from rest, has an acceleration of + 2.6 m/s*s, and has a displacement of + 120 m. Immediately after segment 1, the motorcycle enters segment 2 and begins slowing down with an acceleration of - 1.5m/s*s until its velocity is + 12 m/s. What is the displacement of the motorcycle during segment 2?
First V2 * V2 = Vo2 * Vo2 + 2a2x2, So X2 = V2 * V2 - Vo2 * Vo2
Second VO2 = V1, V1*V1 = VO1*VO1 + 2a1x1
Finally X2 = + 160 m
所以一道看似比较复杂的题目只要找到倒推的逻辑方式, 再多的变量variables都会一一破解。