A <holonomic constraint> can be expressed as $f(q_1,\ldots,q_n,t)=0$, rather than as a genuinely nonintegrable relation among velocities. A fixed rod length is an example. Rolling along a single straight incline also gives an integrable relation $s+R\theta=\text{constant}$ with the sign convention used below; arbitrary rolling in more dimensions need not be holonomic.

Solution

Past exam of the physics 1 paper of the University of Oxford / 2019 / 9 / a / ii / Solution

 Solution (source code)