Newton’s cradle

Newton’s cradle is a device that demonstrates conservation of momentum and energy using a series of swinging spheres. When one sphere at the end is lifted and released, it strikes the stationary spheres, transmitting a force through the stationary spheres that pushes the last sphere upward.
The marbles hurtling down curved inclined channels demonstrate these conservation principles, too.
Find out which reaches faster – a marble down the straight inclined channel or the one down the curved channel.
Also, why the roller in double conical shape apparently defies gravity and rolls up the inclined rods.