Question

一辆车沿平直公路行驶,先以速度V1通过1/3的位移,再以速度50km/h通过其余2/3的位移,若整个位移的平均速度为37

Answer 1

设整段位移是X

(X/3)/V1 + (2X/3)/50 = X/37.5

1/(3V1) + 1/75 = 1/37.5

1/V1 + 1/25 = 1/12.5

1/V1 + 1/25 = 2/25

1/V1 = 1/25

V1 = 25