一列全长100m的火车以72km/h的速度通过一隧道,用了0.5min,则隧道长为
A.2160m
B.2060m
C.660m
D.500m
试题答案
D
v=72km/h=20m/s,t=0.5min=30s.火车通过隧洞运动路程为s=vt=20m/s×30s=600m.s洞=s-s车=500m.
一列全长100m的火车以72km/h的速度通过一隧道,用了0.5min,则隧道长为
A.2160m
B.2060m
C.660m
D.500m
D
v=72km/h=20m/s,t=0.5min=30s.火车通过隧洞运动路程为s=vt=20m/s×30s=600m.s洞=s-s车=500m.