Physics Discussion Question On My Roller Coaster Lab (Energy-Related)?

[wiffellballki]

Homework Statement

We did this roller coaster lab where we had a metal marble roll up and down this roller coaster track.

One of the questions he asked us was "is energy "missing?" explain where it went."

I know friction takes some of it, but I am not good at wording it right to sound good. Help??

Homework Equations

PE= M*g*height
KE= 1/2mv^2

The Attempt at a Solution

I know it has to do with friction taking away some of it, but i need to make it sound good!

 

[Carid]

Well there's some rolling resistance in the metal ball - not a lot though!
Then the track mechanically flexes as the marble passes - that's much more.
Can you hear that marble? - sound energy is very small though.
Heating of the marble and track due to their frictional interaction.
If the marble does any sliding rather than rolling there's plenty of energy loss.
Is the marble magnetic? Induced currents in any nearby conductor will siphon off more energy.

This list is not exhaustive I'm sure.