Three disks have the same mass and the same total kinetic energy.Disk #1 has radius R,disk #2 has radius 2R,and disk #3 has radius 3R.Which one has the highest v_{translational}? A)disk #1 B)disk #2 C)disk #3 D)The all have the same v_{translational}.

Question

Quizplus · Accepted Answer

The total kinetic energy for each disk is the sum of its translational kinetic energy and rotational kinetic energy. Since all disks have the same mass and total kinetic energy, and the only variable is the radius, the translational kinetic energy must be the same for all, as it is independent of the radius. This means all disks have the same translational velocity.

Three Disks Have the Same Mass and the Same Total