A power plant burns coal at 830 K, and exhausts to air at
288 K. If it runs at the Carnot
efficiency, how much input heat
must be fed into the plant to
produce 230,000 J of work?

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.