Question

一小球从A点由静止做匀变速直线运动若到达B点时速度为V到达C点时速度为2V则AB比BC等于多少？会的请帮帮忙

Answer 1

常规法：
由于是匀变速，所以AB和BC所花时间t是一样的。
V(B)
=
V
=
at
S(AB)
=
1/2·at^2
S(BC)
=
Vt
+
1/2·at^2
=
3/2·at^2

平均速度法：
S(AB)
=
V(AB均)·t
=
(0+V)/2·t
=
1/2·Vt
S(BC)
=
V(BC均)·t
=
(V+2V)/2·t
=
3/2·Vt