(1) t=s/v=3km/36km/h=1/12h=5min=300s
W=Pt=30000W*300s=9000000J
答,做功9000000焦
(2)F牵=P/v=30000W/10m/s=3000N
因为匀速运动
所以F阻=F牵=3000N
(1) t=s/v=3km/36km/h=1/12h=5min=300s
W=Pt=30000W*300s=9000000J
答,做功9000000焦
(2)F牵=P/v=30000W/10m/s=3000N
因为匀速运动
所以F阻=F牵=3000N