Question

Two trains are approaching one another from opposite directions on parallel tracks. each train is 150 ft long, but one of the trains is moving at 50 ft/sec, while the other is traveling at only 30 ft/sec. how many seconds elapse from the time the trains first begin to overlap to the time they have completely passed one another?

Answer 1

To find the time it takes for the trains to completely pass one another, we need to calculate the time it takes for them to first begin to overlap and then subtract it from the total time it takes for them to completely pass one another.

Step-by-step explanation:

To find the time it takes for the trains to completely pass one another, we need to calculate the time it takes for them to first begin to overlap and then subtract it from the total time it takes for them to completely pass one another.

Let's first determine the time it takes for the trains to first begin to overlap. We can find this by dividing the sum of the lengths of the two trains by the relative velocity between them:

Time to overlap = (Train length 1 + Train length 2) / Relative velocity = (150 ft + 150 ft) / (50 ft/sec + 30 ft/sec)

Next, we need to determine the total distance the trains travel while overlapping. The distance is equal to the sum of the lengths of the two trains:

Distance while overlapping = Train length 1 + Train length 2 = 150 ft + 150 ft

Finally, we can calculate the time it takes for the trains to completely pass one another by dividing the distance while overlapping by the relative velocity between them:

Time to pass = Distance while overlapping / Relative velocity

Substituting the given values into the above formulas, we can calculate the desired time. Remember to convert the units as necessary.

Answer 2

Time elapsed from the time the trains first begin to overlap to the time they have completely passed one another= 1.875 s

Step-by-step explanation:

Relative velocity of two trains moving in opposite directions is given by

Vr= V1 + V2

V1= velocity of first train=50 ft/s

V2= Velocity of second train=30 ft/s

so Vr= 50+30= 80 ft/s

distance = d= 150 ft

so the time taken= distance/ relative velocity

t=150/80

t=1.875 s