Cyclespanner

Once a heavy thing is traveling at the same velocity as a lighter one, the inertia/kinetic energy the heavy thing has will take it further than the lighter one, which has less inertia/kinetic energy.

Here's a simplistic illustration of what I'm trying to explain....

Both riders traveling at the same speed stop pedaling at the same moment on a flat surface.
Due to friction both will slow, but the lighter will slow quicker as his/her inertia has less kinetic energy.
So after 50 feet the lighter rider will have only traveled (say) 49 feet, so to keep up with the heavy rider must pedal/expend his own energy to match the intrinsic inertial/kinetic energy the heavy rider still has.

I'm no mathematician or physicist, but the above intuitively seems to me to express something fundamental to this topic.

Perhaps someone better qualified would like to comment, please.

I may be wrong.
But I do care.