Question

37. If two trains of length 137 m and 163 m are approaching each other at a speed of 42 km / h and 48 km / h respectively, how long will it take them to cross each other?​

Answer 1

Answer:

They will be clear of each other from the moment they meet 13.2 seconds after.

Step-by-step explanation:

To solve this problem we need to know the relative speed and the distance between the trains.

So, we have:

Relative speed = 42 + 48 = 90 km/h =

= (90 x $\frac{5}{18}$) m/s = 25 m/s

Distance = 137 + 163 = 330 m

Now we know that:

Time = $\frac{distance}{speed}$

Then:

Time = $\frac{330}{25}$ = 13.2 s

Hence, they will be clear of each other from the moment they meet 13.2 seconds after.