Question

Two locomotives approach each other on parallel track. Each has speed of 95 km/h with respect to the ground.If they are initially 8.5 km apart. How long will it take before they reach each other?

Answer 1

It will take 2.68 minutes for them to reach each other.

Step-by-step explanation:

We use the two following kinematic equations, making the final position the same (for the moment they meet each other):

locomotive 1 -->
`x_f=v*t`

locomotive 2 -->
`x_f=8.5\,-\,v*t`

we make the two xf equal, and solve for the time (t) using v = 95 km/h:

`95*t=8.5-95*t\\2*95*t=8.5\\t=8.5/(190)\\t = 0.0447\,\,hours`

converting the hours into minutes by multiplying this value times 60;

t = 2.68 minutes