Jack and Jill, went up the hill

to fetch a pail of water.

Jack fell down,

and broke his crown

and Jill came tumbling after.

Let us examine the physics of this old nursery Rhyme. For this purpose, we will assume that hill is an inclined plane with sufficient roughness. We assume further that while falling down, Jack and Jill are uniform solid cylinders of mass $20 \mathrm{kg}$ and $15 \mathrm{kg}$ respectively. We will assume that Jack is sliding down the inclined plane and simultaneously Jill is rolling purely on the inclined plane as shown in the figure.