1. consider three objects: object a is a hoop of mass m and radius r; object b is a sphere
of mass 2m and radius ; object c is a disk of mass 3m and radius r. show work and draw
a picture.
a. which has the greatest rotational inertia?
b. which has the smallest rotational inertia?

Could someone me find the answer to this problem.

What are atoms of the same element with varying number of neutrons

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.