It depends.
If you start from L.A. and go NORTH, it's 380 miles in 190 min, that's 2 miles/min or 120 MPH.
If you start from L.A. and go SOUTH, it's 25000 miles in 190 min, that's 131 miles/min, or about 8000 MPH.
It's been discussed before, but in order to get up to 100 mph, you need time, and you can't slow down to 20 mph every 30 miles to safely pass through small towns.
First, because it's not legal, second, because it's not safe, third, unless you want to get off in these small towns, it's completely worthless.
A bullet train from LA to Vegas makes sense.
And I could actually see it making a profit.
To Gov. Moonbeam: RE-THINK this!
You can pay your union goon masters their tribute and actually create something of value.
Seriously. How many old fogeys take buses to Atlantic City out of Philadelphia? Lotsa.
Now imagine selling the fogeys on a train that will get you to Vegas in a couple of hours.
And get you home in a reasonable time.
Win-win.
And I'll bet the Vegas casinos would chip in for some of the costs.
Niiice! But at least if you go SOUTH, you can make stops in Mexico and provide humane transportation to thousands of temporary Mexican workers.