1359
Chapter 18
Heat and the First Law of Thermodynamics
Conceptual Problems
1
•
Picture the Problem
We can use the relationship
T
mc
Q
∆
=
to relate the temperature
changes of bodies A and B to their masses, specific heats, and the amount of heat
supplied to each.
Express the change in temperature
of body A in terms of its mass,
specific heat, and the amount of heat
supplied to it:
A
A
A
c
m
Q
T
=
∆
Express the change in temperature
of body B in terms of its mass,
specific heat, and the amount of heat
supplied to it:
B
B
B
c
m
Q
T
=
∆
Divide the second of these equations
by the first to obtain:
B
B
A
A
A
B
c
m
c
m
T
T
=
∆
∆
Substitute and simplify to obtain:
(
)(
)
4
2
2
B
B
B
B
A
B
=
=
∆
∆
c
m
c
m
T
T
or
A
B
4
T
T
∆
=
∆
*2
•
Picture the Problem
We can use the relationship
T
mc
Q
∆
=
to relate the temperature
changes of bodies A and B to their masses, specific heats, and the amount of heat
supplied to each.
Relate the temperature change of
block A to its specific heat and
mass:
A
A
A
c
M
Q
T
=
∆
Relate the temperature change of
block B to its specific heat and
mass:
B
B
B
c
M
Q
T
=
∆

This ** preview** has intentionally

**sections.**

*blurred***to view the full version.**

*Sign up*