Rolling without slipping#

Suppose Ahmed has a sphere (made of solid wood), and a hoop made of heavy metal; and both have the SAME MASS, and both have the SAME RADIUS. Ahmed decides to race the two of them, and let them roll from rest down a flat ramp.

Part 1#

Which one of them will reach the bottom first?

Answer Section#

  • The hoop, because it has less rotational intera, less of its total energy will be taken up by the rotation kinetic energy and more will remain for the translational kinetic energy (so it travels faster

  • The sphere, because it has less rotational inertia, less of its total energy will be taken up by the rotation kinetic energy and more will remain for the translational kinetic energy (so it travels faster

  • They both reach the bottom at the same time, because gravity causes all things to have the same acceleration regardless of their mass.

  • There is not enough information to answer this question.

Attribution#

Problem is licensed under the CC-BY-NC-SA 4.0 license.
The Creative Commons 4.0 license requiring attribution-BY, non-commercial-NC, and share-alike-SA license.