Question

一个做匀加速运动的物体,5 s内通过的位移是60 m,末速度是初速度的3倍,则该物体的加速度为(    )

A．1.2 m/s2

B．1.8 m/s2

C．2.4 m/s2

D．3.6 m/s2

Answer 1

C

5 s内的平均速率v==m/s="12" m/s                                     ①
根据v=                                                             ②
根据v_t=3v₀                                                                            ③
联立①②③得v₀="6" m/s,v_t="18" m/s
由v_t=v₀+at得a==m/s²="2.4" m/s²,故C正确.