http://www.ck12.org Chapter 13. Heat
http://demonstrations.wolfram.com/HeatCapacityOfSolidsInTheDebyeApproximation/
Check Your Understanding
One kilogram of the each of the substances in table 13.1.1 has 100 J of energy transferred to it at an initial temperature
of 20°C. Which substance experiences the largest increase in temperature?
Answer: Since silver has the smallest specific heat, it has the largest temperature rise.
Illustrative Example 1
A United States penny,Figure13.7, is made almost entirely from zinc. The penny has a mass of 2.5 g and an initial
temperature 20°C.
FIGURE 13.7
A United States penny is almost completely made from zinca. Find the temperature increase of the penny if 380 J is transferred to it.
Answer:
Since the SI units of the specific heat contain kilograms, we must express 2.5 grams in kilograms:
( 2. 5 g)^11000.^000 kgg = 0. 0025 kg.
We should expect the temperature to increase to be greater than 1°C.
∆Q=cm∆T→ 380 J=
(
(^390) KgCJ
)
( 0. 0025 kg)∆T→∆T=( 390 J^380 J
KgC)(^0.^0025 kg)
= 389. 74 → 390 ◦C
b. What is final temperature of the penny?
Answer:
Since the penny was initially 20°C and the change in temperature was 390°C, the final temperature of the penny is
410°C. This is ten degrees away from its melting temperature.
Check Your Understanding
a. Equal amounts of zinc and silver, at the same initial temperature, absorbed the same amounts of heat. For every
one degree increase in the temperature of the zinc, find the increase in the temperature of the silver.
Answer: The ratio of the specific heats of zinc to silver is
(^390) kgJ◦C
(^230) kg◦JC=^1.^696 →^1 .70.