exponential function in a game for calculating difficulty

[bootv2]

I want to build a formula that would roughly follow this graph. So I can calculate all difficulty related variables from a number in between 1-100(0 can be ignored since that would bring the game to a standstill)

[bootv2]

And, the max velocity is not 100, but 1000

[buddy]

You need way more data points if you want to get a good match. Otherwise, anything through the two points (0,0) and (100,1000) is pretty much gonna work.