For a spring hanging vertically from a fixed point, suppose the spring constant, k, is a function of the distance from the fixed point to the other (lowest) end of the spring (for example; the diameter of the spring's coils changes along the length of the spring) .

What ODE reflecting this situation will yield solutions for the harmonic motion of the spring after it is stretched from its equilibrium position?

https://www.maplesoft.com/applications/view.aspx?SID=3707

The worksheet below animates a hamster running back and forth on a linear floor within a wheel. Its motion is such that the wheel remains stationary.

What math would describe the hamster running back and forth such that the wheel oscillates with a constant frequency and the floor's vertical angle oscillates between plus and minus an angle greater than zero and less than 2 Pi?

Hamster_in_wheel.mw

The uploaded worksheet describes a mechanics scenario which I would like to animate.

While I understand the expression for the kinetic energy of the torus, the term containing cos(theta) within the expression for the KE of the pearl baffles me.

From which physics aspect of the scenario does this term derive?

Pearl_in_torus.mw

The worksheet below animates the flattening of a tetrahedron by expanding one of its faces, namely its triangular base.

I would like to animate the flattening of an octahedron so that it assumes the 2D figure resembling the Morley triangle which is included in the worksheet.

Are there documents on the web explaining the technique for doing so? Is there a Maple worksheet available on the web demonstrating the desired animation?

Flatten_a_tetrahedron.mw