Grrr i need help

[DeStyle]

Energy is not really "conserved". EDIT: I ment that not ALL of the energy is conserved :P.

A cart goes down, with speed, then goes uphill again. However
the force pushing the cart up again is lower than the force the
cart aquired while going downhill. Therefore a cart will never drop
down and end up higher than the point from which it was dropped.


The rollercoasters try to maintain as much speed/force as
possible (so that the ride goes faster) this is done by reducing
the friction the wheels of the cart make (if there was no friction
the cart would land at the EXACT height it got dropped from),
less friction means less decrease in speed per meter.

I would answer something along the lines of this:

"Rollercoasters gain speed while rolling downhill. As much
energy as possible is conserved by having the least friction
possible between the wheels of the carts and the rails
of the rollercoaster."