Uniformly accelerated train problem

[jlopez]

After picking up passengers, a train accelerates uniformly until its speed is 100 km/hr at t= 300 s. If during this time it is traveling on a planar path that approximates the circle and line shown in the figure, find the magnitude of the train's acceleration when (a) t = 1 min and (b) t = 2 min.

link to figure:
http://i22.photobucket.com/albums/b346/lopezjose/IMG00264-20100502-0017.jpg

I'm not sure what frame of reference to use and how to start this problem

normal acceleration is v^2/r
tangental acceleration is dv/dt

 

[tiny-tim]

Welcome to PF!

Hi jlopez! Welcome to PF!

(try using the X² tag just above the Reply box )

First, use one of the standard constant acceleration equations to find the linear (tangential) acceleration.

Then find the position at 1 min and 2 min, and if the path is curved then, find the speed and the centripetal acceleration (the normal acceleration).