Consider what you know of real world materials and interaction, because I did a brief search attempting to find a table (similar to friction tables?) of relative elasticity values but didn't find anything.
If it's something like a golf ball on concrete, maybe give it 50-60m?
A solid, rubber ball (lacrosse) maybe 70 or so?
A volleyball, maybe 10-20m?
As long as you have a general idea of what the two surfaces are, you should be able to come up with a reasonable estimate that won't look too outrageous. Just test it out and see if it looks normal to you. Humans have a pretty good ability to recognize when something "shouldn't be happening".