# Deisel train kinematics

1. Nov 23, 2007

### scotthands

1. The problem statement, all variables and given/known data

A deisel train accelerates uniformly from rest to reach 60km/hr in 6 minutes, after which the speed remains constant.
Calculate the total time taken to travel 6km and the acceleration.

2. Relevant equations
s= ut
v= u+at
s=ut + 0.5*at^2

3. The attempt at a solution
I'm not sure how to incorporate the accelaration part into the question.
I tried t=(v-u)/a but idon't know what to put in for the acceleration.

Last edited: Nov 23, 2007
2. Nov 23, 2007

### qspeechc

That is not a question.

3. Nov 23, 2007

### scotthands

yeah i accidentally entered the post before i finished it, it's finished now.

4. Nov 23, 2007

### qspeechc

Well the time taken to accelerate is 6min, because we are given that.

First find the distance travelled in the 6mins it is accelerating.

6mins = 1/10 hours. We must find the acceleration.

Re-arrange v= u+at for acceleration:

a = (v - u)/t = 60/(1/10) = 600 km/h^2

Now find the distance it travels:

s=ut + 0.5*at^2 = 0 + 0.5*600*(1/10)^2 = 3km

Therefore the train still has 3km left to go, but now it is travelling at a constant 60km/h, so the time taken is:

s = ut
so:
t = s/u = 3/60 = 1/20 of an hour = 3mins

So the total time for the journey is 9mins

5. Nov 23, 2007

### scotthands

thank you

6. Nov 23, 2007

My Pleasure.