A bit of a strange request:
My 13 y/o son is presenting his research project on the difference in spin time of a yoyo with a stainless steel 10-ball bearing versus a gold-plated 10-ball bearing. I have found the coefficient of friction for the static gold on gold (0.49), but could not find the kinetic COF.
Any guidance to where we can find this?
Many thanks,
Maria