Originally Posted by **xtheunknown0** The solutuion to question 12 of http://www.vcaa.vic.edu.au/vce/studi...ysics22004.pdf is that potential energy is converted to kinetic energy:
1/2 * mv^2 = mgh
but say there were a point Z at the 'corner' of the left curve (so on the same level as X). Surely there was some initial kinetic energy *and* potential energy that got all converted to the kinetic energy at the level where Y is.
xtheunknown0 |

I'm not quite sure what you are saying about point Z. If the car is to get to Z, which is on the same level as X then it would have to have been pushed, ie would have to have been given some kinetic energy, as you say. But the ground at point X is (presumably) slightly sloped so the car will start to move down the slope without someone giving it kinetic energy, so we don't need the extra push.

I'm not sure I answered your question. Please let me know.

-Dan