You might check your math early in the paper.

500/10 = 50, not 20.

But, you can look at speeds as limits.

Velocity = Distance / Time.

Set Time = ε, as ε < 0.

Then look as the limit as the non zero ε approaches zero.

Traveling between two points of a finite distance, with a non-zero time ε. One always also gets a finite, velocity, less than infinity, d/ε.

If you set your time to be zero, and your velocity to be infinite, then you might also conclude that you would be unable to travel (and stop) at a finite distance.

What is the distance that you travel in zero time --> zero.

What is the distance you you travel at an infinite velocity at a finite non-zero time, for example... 1 second.. well, the distance is now also infinite.

If you think of asymptotes, you can always approach the asymptote, but you can never quite hit it.

Incidentally, if you set an asymptote at say, velocity = c. Then, you put in v=c+1, you get some quite screwy stuff.