At first, you might think that it wouldn't make a difference because the cars are attached and so they're basically going at the same speed at any given point in time. But what makes the ride in the back of the roller coaster feel so different than the ride in the front of the roller coaster is that although the cars are going the same speed at any given point in TIME, they aren't going the same speed at any given LOCATION on the track.
Here's why: There isn't any motor that moves the cars all along the track, a motor pulls the cars up that first hill, storing a bunch of potential energy, and after that the cars are just driven mostly by the potential energy that is built up, and gravity. So the cars are moving at different speeds as they move along the track. The velocity picks up as they are going DOWN a hill because of gravity, and slows down as they go UP a hill.
So what makes the back car FEEL like a more exciting ride is that it is always going faster than the front car when they pass over the hills. That's because the cars are decelerating as the front car goes over a hill because gravity is pulling against the force that moves them forward, but by the time the last car is going over the hill, all of those front cars are being pulled down the next hill by gravity and the whole train of cars is accelerating.
It depends on the actually roller coaster design, but in the vast majority of roller coasters you will get more air time in the back car as you go over those hills. Air time is that feeling that your going to go flying out of the car.
So a lot of people think the back car is the best ride, but some people prefer the front car because you get an unobstructed view and can feel the wind in your face. Some people sat that those visual cues you get of drops and near misses are a huge part of the ride, which I think is really interesting because I don't really like roller coasters, but I LOVE space mountain at Disneyland, I just love that it's dark and I don't get as scared, it's really the only roller coaster I go on. And I'll go again and again if there aren't any lines. But I'm a real scardey cat. The one thing about roller coasters that I think most people agree on is that the ride in the middle cars isn't as fun as either the front or the back.
And a final interesting thing is that your body actually feels changes in velocity more than actual velocity, so a ride that is actually slower but has lots of changes in velocity can feel more exciting than a ride that is faster but going at a more constant velocity.
