Identical aluminum blocks are attached to the cool ends of two solid cylindrical rods…
PHYSICS · Multi-part · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter
Problem
Identical aluminum blocks are attached to the cool ends of two solid cylindrical rods that are held side-by-side. One rod is made of copper and the other of glass. Each rod has the same length and the same cross-sectional area. The hot ends of the rods are pressed against a thermal reservoir maintained at 150∘C. Initially the entire apparatus is at 20∘C. The blocks are thermally insulated on every surface except the face that contacts the rod.
Assume that no energy is lost to the environment except through the rods themselves.
(a) Describe qualitatively which aluminum block will reach 40∘C first. Identify the material property of the rods most responsible for any difference and explain your reasoning.
(b) The two aluminum blocks are observed to reach 40∘C at noticeably different times, even though both blocks have the same mass and specific heat. Explain how the difference in the heating rates of the two blocks is consistent with conservation of energy.
(c) Suppose the mass of each aluminum block were doubled while every other aspect of the setup remained the same. Describe qualitatively how this change would affect the time required for each block to reach 40∘C, and explain your reasoning.