# Thread: Non-Uniform Motion in a circle

1. ## Non uniform motion in a circle

Another question i cant get my head around (this ones a bit long):

1) express each force in vector form

2)Derive equation of motion for particle p1 and p2

3)write down distance p2 has fallen after time t and deduce magnitude of acceleration of p2 as r*theta where theta is magnitude of angular acceleration

4) show that

Magnitude of angular acceleration = g(2-cos(theta))/3R

5) Show that magnitude of normal reaction of the cyclinder on P1 is

mg(5sin(theta)-4*(theta))

2. use polar co-ordinates for P1 and Cartesian Co-ordinates for P2

3. ## Non-Uniform Motion in a circle

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?