Car passing a 1km train at different speeds and directions

[monkfishkev]

Homework Statement

A car moving at 60km/h meets a train of length 1km moving at 40km/h along a track parallel to the road. What distance does the car travel in passing the length of the train given that they travel a) in the same direction, or b) in opposite directions?

Homework Equations

So I converted everything into metres and used
S = ut + 1/2at^2

The Attempt at a Solution

By adding 1000m to s(displacement) of the car, managed to get 180seconds which gave 3km
In the opposite direction I got 36 seconds which gave 600m.

There was no answers given to the question set and really need a second opinion to these answers. They seem to make sense but I am still unsure.

Thank you

 

[voko]

Looks good to me.

 

[CWatters]

The answers look right. I used the relative speed between car and train to calculate the time taken to pass the 1km long train, then worked out how far the car would travel along the ground in that time.