Question that I dont know how to answer

[shadow1010]

Hi Guys,
we were given this question, and I have no idea where to start.

A car is coasting without friction toward a hill with height 'h' and ratius of the curvature is 'r'.
(a) what initial speed 'vo' will result in the car's wheels just losing contact with the roadway as the car crests the hill?
(b) what happens if the initial speed of the car is greater than the value found in part (a)?

I have figured out that there are no non-conservative forces acting on the car, so the work (conservative) is equal to the work (total) but I don't know where to go from there...any suggestions?

 

[Mindscrape]

So, how does the normal component look all along the hill? Is it the biggest at the top of the hill, is it the smallest? What forces are acting on the car as it goes up the hill? Why am I so concerned about the normal anyway?

You might want to break the problem (a) up into a couple problems, what velocity it needs at the top of the hill to fly off and then how that velocity relates to the initial one (you're energy thoughts for this part are good).