1. The problem statement, all variables and given/known data A car moves along a straight, but hilly road, at a constant speed. There is a crest and dip in this road, both with a radius of 250m. a) As the car passes over the peak of the crest, the normal force is half the 16kN weight of the car. What is the normal force at the bottom of the dip? // Here I'm already noticing that circular acceleration must be equal to gravity. so that 16kN = 2N = m(g+ ac). The normal force is a contact force. It opposed what is imposed, given the surface it's sitting on. In this case, the normal force equals mg or the force towards the centre of the circle. But not both. Why is that? b) What is the greatest speed that the car can move without leaving the road at the top of the crest. // Once you pass the crest, you're relying on gravity to maintain your circular motion. So if ac>g at the peak, then your velocity will be too great for gravity to keep you on that curve. Your maximum velocity is v = √(gr) c) Moving at the speed found in (b), what would your normal force be at the bottom of the dip? // Given my confusion in (a), I'm having issues conceptualizing this one. But, I believe it should also be equal to mg, or mac, but not both.