Given the 2 equations below...

-T*sin(theta(t)) = m*(diff(X(t), t, t)+L*(diff(theta(t), t, t))*cos(theta(t))-L*(diff(theta(t), t))^2*sin(theta(t)))

 T*cos(theta(t))-m*g = m*(diff(Y(t), t, t)+L*(diff(theta(t), t, t))*sin(theta(t))+L*(diff(theta(t), t))^2*cos(theta(t)))

which command(s) will eliminate T and m to give the ODE below?

 L*diff(theta(t), x, x)+(diff(X(t), x, x))*cos(theta)+(diff(Y(t), x, x)+g)*sin(theta) = 0

In the uploaded worksheet a block slides up the Hill from an initial position at an initial horizontal velocity. The block's motion is subject to sliding friction.

How can the equations of the block's motion be obtained to include the effects of gravity and friction?

It may simplify the answer to end the block's upward motion when gravity and friction bring it to an instantaneous halt.

Block_sliding.mw

I would like to animate the motion of a bicycle racer on a classic velodrome track i.e. one with varied vertical and horizontal curvatures along its length.

Is there a source which explains the math expressions which model the shape of such a track?

`~`[int](convert(convert(series(x^x, x), polynom), list), x = 0 .. 1)

Can this sequence (produced above in list form) be displayed as 1, -1/2^2, 1/3^3, -1/4^4, 1/5^5 -1/6^6 etc.

That is with the powers unevaluated.

Please describe the step-by-step application of the rules of differentiation which produce this derivative:

diff(a(x)^b(x), x) =        

a(x)^b(x)*((diff(b(x), x))*ln(a(x))+b(x)*(diff(a(x), x))/a(x));