If you want a function to return those variables to the workspace, you'll need to declare it as:
function [mass speed velocity] = myvariables()
and call it as
[mass speed velocity] = myvariables()
Alternatively, you can assign those variables in either the calling, or base workspace (look up the help for assignin or evalin)
Alternatively, again, you can declare the variables as global in every function you want to use them, AND in the base workspace.
