Two trains

Through the bridge, long l = 240m, the train passes through the constant speed at time t1 = 21s. A train running along the traffic lights at the edge of the bridge passes the same speed at t2 = 9s.

a) What speed v did the train go?
b) How long did it take for a train driver to cross the bridge?
c) What is the L train length?
d) How long will it take for a train to overtake in the same direction with the same length but half the speed?
e) How long will it take for a train to overtake in the opposite direction with the same length but half the speed?

Correct answer:

v =  20 m/s
L =  180 m
t3 =  12 s
t4 =  36 s
t5 =  12 s

Step-by-step explanation:

l=240 m t1=21 s t2=9 s  L=9 v L+240=21 v  L9v=0 L21v=240  Row2Row1Row2 L9v=0 12v=240  v=12240=20 L=0+9v=0+9 20=180  L=180 v=20=20 m/s
L=180=180 m
t3=l/v=240/20=12 s
t4=vv/22 L=2020/22 180=36 s
t5=v+v/22 L=20+20/22 180=12 s



Did you find an error or inaccuracy? Feel free to write us. Thank you!







Tips for related online calculators
Do you have a linear equation or system of equations and looking for its solution? Or do you have a quadratic equation?
Do you want to convert length units?
Do you want to convert velocity (speed) units?
Do you want to convert time units like minutes to seconds?

You need to know the following knowledge to solve this word math problem:

Related math problems and questions: