Obtain a small grinding wheel and observe its surfaces using a magnifier or a microscope, and compare

Question:

Obtain a small grinding wheel and observe its surfaces using a magnifier or a microscope, and compare with Fig. 9.6. Rub the periphery of the wheel while pressing it hard against a variety of flat metallic and nonmetallic materials. Describe your observation regarding
(a) The type of chips produced,
(b) The surfaces developed, and
(c) The changes, if any, to the grinding wheel surface?