A truck tractor pulls two trailers, one behind the other, at a constant speed of 100 km/h. It takes 0.640 s for the big rig to completely pass onto a bridge 390 m long. For what duration of time is all or part of the truck-trailer combination on the bridge?
4 answers
please show work
100km/h = 27.78m/s
390m / 27.78m/s = 14.038s
14.038 + 0.640s = 14.679s
390m / 27.78m/s = 14.038s
14.038 + 0.640s = 14.679s
The length of the tracktor with two trailers is
d=v•t= 27.78•0.64 = 17.78 m.
L=l+d=390+17.78=407.78m
Δt=L/v=407.78/27.78=14.68 s.
d=v•t= 27.78•0.64 = 17.78 m.
L=l+d=390+17.78=407.78m
Δt=L/v=407.78/27.78=14.68 s.
what does the L stand for?