Old problem about one tunnel through the earth

About this promlem see here http://communities.ptc.com/docs/DOC-2140

3 question:

1. Is there one symbolic solution (im Mathcad) of this problem of... 42 min?

2. What value og g we must use?

3. Good links on solutions?

An Animation:

http://communities.ptc.com/videos/1982

The task

The Challenge Problem from PTC

A train leaves New York at 9:45am EDT, heading for San Francisco...

The train system consists of a straight-line tunnel connecting the two cities. The train uses a MAGLEV (magnetic levitation) system consisting of permanent magnets in the tracks and superconductive electromagnets in the train. To accelerate it uses a combination of electromagnetic force and gravitational pull of the Earth. The deceleration comes also from the gravitational pull of the Earth, as well as aerodynamic drag of the train.Problem: Compute the arrival time in San Francisco assuming constant propulsion force.

See the attac