车重:G=mg=0.8x10^3kgx10N/kg=8000N匀速行驶时,牵引力=阻力..F=f=0.1G=0.1x8000N=800N车速:v=72km/h=20m/s时间:t=5min=300S做功:w=Fs=800Nx20m/sx300s=4800000J功率:p=w/t=4800000J/300s=16000w不明追问。
