Some questions below, involving strategies, regarding the following problem:
A hoop of weight $20$ Newtons can rotate freely about a pin fixed in a wall. A string has one end attached to a pin, runs round the circumference of the hoop to its lowest point, and is then held horizontally at its other end. A gradually increasing horizontal force is now applied to the string, so that the hoop begins to rotate about the pin. Find the tension in the string when the hoop has rotated through $40$ $degrees$.
- Even though there is circular motion here, with the string at least, - can this be modelled with triangulation between $W$, $T$ and one point of the hoop i.e. make a right angled triangle for which moments can be worked out?
For instance $W$ = $20 Newtons$ initially and then $W$ = $20cos(40)$ after movement.
- Would this be accurate enough or would the fact that part of the "path" of the string is circular even though no specfic information about the radius or circumference is given? A lot of scenarios involve ladders or rods that are straight.