①0-2s段升降机的加速度a1:
a1=(Vt-V0)/t=(3-0)/2=1.5(m/ss)
②升降机上升的最大高度:
H=H1+H2+H3
=(a1/2)(t1)(t1)+(V2)(t2)+(V03)(t3)+((a3)/2)(t3)(t3)
=(1.5/2)×2×2+3×8+3×4+(-0.75/2)×4×4
=3+24+6
=33(m)
③0-10s段升降机的平均速度v:
V=(S1+S2)/(t1+t2)
=(3+24)/(2+8)
=2.7(m)
④若升降机从水平地面上开始运动,则16s末时升降机距离地面的高度h:
h=H+((a4)/2))(t4)(t4)
=33+(-0.75/2) ×2×2
=31.5(m)
注:a4=a3
答:………………………………………………………….