Parametric Equations for Tank's Continuous Track: Explained and Demonstrated

[Sistine]

Homework Statement

A tank is traveling in a straight line we look at the side on view of the tank and consider its continuous track in contact with the x-axis. Its wheels have radius R and the distance between he centers of the wheels is L (The continuous track is wrapped around the wheels). Consider a point M(t) on the track.

We suppose that at t = 0 the point M(0) = (0, 0) is on the ground under the centre of
the back wheel. Give a parametrisation of the curve with respect to the first coordinate
(denoted by t) of the centre of the back wheel.

Homework Equations

The Attempt at a Solution

I'm having diffuculty understanding whether I should get the parametric equation of the curve traced by a fixed point on the track, or the parametric equation of the track in a stationary moving frame

 

[LCKurtz]

Draw a side view with the wheels resting on the x axis. Imagine a piece of chalk glued to the wheel at the origin. As the wheels roll to the right the chalk will trace out a curve on your paper. I think that's the curve for which the equations are required.