Use the same technique that you employed in Parts G-I to decide whether the second collision is elastic. Find the kinetic energy KBC(ii) of the system of spheres B and C before the second collision. Express your answer with the appropriate units.

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.

i think its c if i'm wrong