The diagram shows a wheel of radius r rolling to the right along the x -axis on horizontal ground, with its centre moving at constant speed v. Relative to O as origin, the position vector of a point A on the rim of the wheel at time t after leaving the origin is given by the expression r = vt i + r sin(wt) i + r j + r cos(wt) j, where w is the angular speed of rotation around the centre of the wheel.
In the diagram, the angle wt is measured clockwise starting from the vertical. If the wheel is to roll without slipping, then any point such as A must be momentarily at rest when it touches the ground.
1. Show the development of the expression for the position vector of A.
2. (a) Use a spreadsheet or other technology to produce a graph showing the actual path of A as the wheel rolls. (This would be the path seen by an observer at night if point A was somehow illuminated.)
(b) Show mathematically that point A never moves to the left.
Have no idea how to do the questions above, any help would be greatly appreciated.