myheadhurts

is there not a natural reaction force due to the particle being in contact with surface of the cylinder?

I am a bit confused by this question(see attached image). This has been posted before but im not any further forward. My problems are: P1 - has this got the following forces acting on it: Weight, Tension, and Natural reaction force? and thus does the equation of motion end up as: mr''= -|T|er - (mgcos a)er - (mgsin a)eo + |N|er where er and eo are the radial and tangential components respectively Then is it a case of gathering the similar terms and resolving in the er direction to get: ml0'^2 = mg cos a - |T| P2 - is this just experiencing the tension of the string and its own weight?