I am really envious of my 10 year old daughter Alyssa who will be going to Hershey Park this summer while on a trip with her grandparents. She is pretty brave, so she may ride this unless the height restrictions stop her.
I once rode a coaster with a 4G turn, the Goliath at Six Flags Magic Mountain. The high speed, high g turn was so intense I felt like an elephant was sitting on my chest. spent the rest of the day coughing and hacking trying to recover from the compression on my lungs. Of course I would do it again anyway
Now if we could just build a tunnel through the earth without melting.
A Tunnel directly through the center of the earth would be about 7926 miles long. The 42 minute journey would be at an average speed of 11,322 mph, with a max speed of about 27,490 mph. For the first half of the ride you would experience 0g or near weightlessness. For the second half of the ride your would experience 2g or twice your own body weight. Tunnels that went through the earth without intersecting the center would experience varied speeds and g forces. But the journey would always take 42 minutes.
All this neatly assumes that friction, and its accompanying terminal velocity, is absent. So on top of making the tunnel out of some material that does not melt at the earth's core temperature of somewhere between 5,000 to 7,000 degrees Celsius, the tunnel must also be a sealed vacuum and the vehicle must travel without direct contact to the side walls.
When terminal velocity is figured in (the speed at which drag produced by the atmosphere is equal in force to the acceleration of gravity) you would end up in a situation where the top speed of the vehicle would not be enough to overcome gravity on the way out of the center of the earth. The vehicle would come to a stop short of the end of the tunnel and begin falling back towards the center. The oscillation from one side of the tunnel to the other would continue with the distance from the core getting shorter with each trip. Eventually the vehicle would come to a complete rest at the center of the earth.
But the math used in the original idea is a very interesting example of concepts of acceleration by gravity.
