功率40kw,25min做功为:(40x1000x25x60)焦耳
匀速行驶,行驶的路程为:s=vt,P=Fv,P=40x1000x25%,F是阻力,匀速行驶牵引力等于阻力
汽油的质量:mq=40x1000x25x60
解:1)P=40KW=40000W, t=25min=1500s
W有=Pt=40000Wx1500s=6x107J
2)由W有=Fs=fs得s=w/f =6x107J/2000N =3x104m
3)Q=W有/25% =2.4x108J
m=Q/q=2.4x108J/4.6x10^7J/kg =5.2kg
有疑惑可追问,望采纳
我不会作这个题