7. Four round objects, each with the same mass and radius, are
held at the top of the ramp shown and allowed to roll, without
slipping, down the ramp. The objects are: (1) a hoop,
(2) a solid disk, (3) a solid sphere and (4) a hollow sphere.
a. Without performing any calculations, rank the speeds of
the objects when the reach the bottom of the ramp.
Using energy considerations, explain your reasoning.
b. Without performing any calculations, explain how your results change if the radii of the objects
change. Explain your reasoning.