Please tell me if I'm wrong with an explanation (A Level explanation please).
You feel the heaviest at the bottom of the ferris wheel because in order for there to be a centripetal force, the normal force has to increase to provide the force. Therefore, your weight decreases because Newton Third's Law states that the two pairs of forces are opposite and equal. (But I didn't think it was possible to decrease your weight and so I think I am wrong). You feel the lightest or weightless at the top of the ferris wheel because the centripetal force required is opposite to the normal force, thus the normal force needs to decrease in order to provide a force for the inward acceleration. As the normal force decreases, your weight must therefore also decrease and therefore you feel weightless.
I have a feeling this is wrong because you can't physically change your weight on Earth (unless you exercise) and so can someone provide me with some explanation as to why you feel weightless.
Oh, and does the centripetal force $= mg - R $?
Edit: I now understand that weight and the normal reaction force are not an interaction pair so Newton's Third Law does not apply.
So, does this mean that the circular motion is due to the normal reaction force only increasing?