CHAPTER 4 HEAT AND THE SECOND
LAW OF THERMODYNAMICS EXAM
QUESTIONS WITH COMPLETE
ANSWERS
Heat Transfer ( 1st part of the 2nd Law) - ANSWER-Heat always moves from a warmer
place to a cooler place.
Hot objects in a cooler room will cool to room temperature.
Cold objects in a warmer room will heat up to room temperature.
Heat will not flow spontaneously from a cold to a hot body.
If a cup of coffee and a red Popsicle were left on the table in this room what would
happen to them? Why? - ANSWER-The cup of coffee will cool until it reaches room
temperature. The Popsicle will melt and then the liquid will warm to room temperature.
Heat is Lost ( The 2nd part of the 2nd Law) - ANSWER-Energy always goes from a
more useful to a less useful form.
Whenever energy is transformed form heat to another type, some heat is lost.
EX: Some of that heat must be dumped into the environment & is unavailable to do
work - From heat to an electrical current
Disorder ( The 3rd part of the 2nd Law) - ANSWER-Be described by the term Entropy:
All isolated systems will spontaneously tend toward disorder.
Every isolated system become more disordered with time.
Your house goes from clean to messy more easily than vice versa, new car becomes
scratched and dirty, we all age as our bodies gradually wear out.
Ordered System - ANSWER-1 in which a # of objects are positioned in a completely
regular & predictable pattern.
Disordered System - ANSWER-Contains objects that are randomly situated, without any
w/o any obvious pattern
Which is more likely - ANSWER-Disorder is more probable than order.
Temperature - ANSWER-How hot or cold something is in comparison to another object
Thermometer - ANSWER-Used to measure temperature
Why Kelvin versus Celsius? - ANSWER-Kelvin has no negatives
LAW OF THERMODYNAMICS EXAM
QUESTIONS WITH COMPLETE
ANSWERS
Heat Transfer ( 1st part of the 2nd Law) - ANSWER-Heat always moves from a warmer
place to a cooler place.
Hot objects in a cooler room will cool to room temperature.
Cold objects in a warmer room will heat up to room temperature.
Heat will not flow spontaneously from a cold to a hot body.
If a cup of coffee and a red Popsicle were left on the table in this room what would
happen to them? Why? - ANSWER-The cup of coffee will cool until it reaches room
temperature. The Popsicle will melt and then the liquid will warm to room temperature.
Heat is Lost ( The 2nd part of the 2nd Law) - ANSWER-Energy always goes from a
more useful to a less useful form.
Whenever energy is transformed form heat to another type, some heat is lost.
EX: Some of that heat must be dumped into the environment & is unavailable to do
work - From heat to an electrical current
Disorder ( The 3rd part of the 2nd Law) - ANSWER-Be described by the term Entropy:
All isolated systems will spontaneously tend toward disorder.
Every isolated system become more disordered with time.
Your house goes from clean to messy more easily than vice versa, new car becomes
scratched and dirty, we all age as our bodies gradually wear out.
Ordered System - ANSWER-1 in which a # of objects are positioned in a completely
regular & predictable pattern.
Disordered System - ANSWER-Contains objects that are randomly situated, without any
w/o any obvious pattern
Which is more likely - ANSWER-Disorder is more probable than order.
Temperature - ANSWER-How hot or cold something is in comparison to another object
Thermometer - ANSWER-Used to measure temperature
Why Kelvin versus Celsius? - ANSWER-Kelvin has no negatives
