Lab Question

[MJC8719]

So, we just did our lab on KE and GPE....the usual one on an air cart with paper clips....and i have been having trouble with a couple of the questions

Why would we have measured the distance traveled from the center of the cart and not the end like previously?
Is it something to do with the center of mass....or the fact that work is concentrated at the center

Why is it good to make the distance covered as long as possible
Maximum time for the work to take place during maybe??

What other types of energy were present?

Besides GPE and KE...what other types of energy are tehre

[CaptainZappo]

What other types of energy were present?

Besides GPE and KE...what other types of energy are tehre

Well one obvious addition is thermal energy. Gravitational potential energy and kinetic energy would not be completely conserved if there was any friction involved. The frictional force would have done work on the cart and converted some of that energy into thermal energy. Energy could also be lost to sound (if the cart bumped into something, etc...).