Question

质量为2000kg的汽车沿着长为5.4km的盘山公路匀速行驶,当它从山脚行驶到高为0.4km的山顶时,耗时20min,.

Answer 1

m = 2000kg

L = 5.4*1000 = 5400m

H = 0.4*1000 = 400m

t = 20*60 = 1200s

F = 4000N

牵引力做功W = FL = 4000*5400 = 21600000J

牵引力的功率P = W/t = 21600000/1200 = 18000W