一小车以10m/s的速度行驶了1km 后,又以54km/h的速度行驶了10s,休息10s后,用3min行驶了1
1个回答

(1)∵v=

s

t ,

∴小车的运动时间t 1=

s 1

v 1 =

1000m

10m/s =100s;

(2)v 2=54km/h=15m/s,

∵v=

s

t ,

∴小车的路程s 2=v 2t 2=15m/s×10s=150m;

(3)小车的总路程s=s 1+s 2+s 3+s 4=1000m+150m+0m+1850=3000m,

运动总时间t=t 1+t 2+t 3+t 4=100s+10s+10s+180s=300s,

小车全程的平均速度v=

s

t =

3000m

300s =10m/s;

答:(1)第一段用时100s.

(2)第二段的路程是150m.

(3)全程平均速度是10m/s.