Author Question: Aluminum rod 1 is 1.0 m long with cross-section area 2.0 cm2 . Aluminum rod 2 is 2.0 m long with ... (Read 205 times)

jparksx · **on:** Jul 28, 2018

Aluminum rod 1 is 1.0 m long with cross-section area 2.0 cm2 . Aluminum rod 2 is 2.0 m long with cross-section area 4.0 cm2 . Aluminum rod 3 is 3.0 m long with cross-section area 9.0 cm2 . If each rod has the same temperature difference applied across its ends, which rod has the greatest rate of transfer of energy between its ends?
a. 1
b. 2
c. 3
d. 2 = 3, both greater than 1
e. They each have the same rate.

Question 2

Beryl states that insulation with the smallest possible thermal conductivity is best to keep a house warm in winter, but worst for keeping a house cool in summer. Sapphire insists the reverse is true: low thermal conductivity is good in the summer, but bad in the winter. Which one, if either is correct?
a. Beryl, because low thermal conductivity results in low heat transfer.
b. Beryl, because low thermal conductivity results in high heat transfer.
c. Sapphire, because low thermal conductivity results in low heat transfer.
d. Sapphire, because low thermal conductivity results in high heat transfer.
e. Neither, because low heat transfer is desirable both in summer and in winter.