It’s fairly straight most of the way from about the zoo to the curve. past the north philly station. Read about how fast the trains can accelerate. amazing.
These trains don’t accelerate that fast. IIRC, someone had posted the acceleration rate for these Amtrak engines. I think it took 3 or 4 minutes to reach something near this speed (106) from a dead stop, probably at least a minute, maybe more to get there from the 70MPH limit in the section before the curve.