Week 4-5 - Energy Transformations, Efficiency, and PV Diagrams Capabilities
Description
12 Physics (12 Physics Fundamental Skills) Quiz on Week 4-5 - Energy Transformations, Efficiency, and PV Diagrams Capabilities, created by Ryan Elwell on 09/12/2019.
What is the total change in energy for a closed cycle PV diagram?
Answer
Always equal to zero
Equal to the work done by the system
Equal to the work done on the system
The total area under the PV diagram curves
Question 6
Question
We define thermal efficiency as:
Answer
The ratio of heat input to work output
The ratio of heat input to cold output
The ratio of cold input to heat output
The ratio of work done to cold output
Question 7
Question
An automobile engine has an efficiency of 20% and produces an average of 23,000 J of mechanical work per second during operation. How much heat input is required?
3 SF.
E = [blank_start]115,000[blank_end] Joules
Answer
115,000
Question 8
Question
An automobile engine has an efficiency of 20% and produces an average of 23,000 J of mechanical work per second during operation. How much heat is discharged as waste heat from this engine per second?
2 SF.
E = [blank_start]92,000[blank_end] Joules
Answer
92,000
Question 9
Question
What is unique about a Carnot Cycle heat engine?
Answer
It has no energy loss and is 100% efficient
It has equal hot and cold work inputs
It has double the heat input as cold output
It has the maximum possible efficiency of 99%
Question 10
Question
1200 J of heat flowing spontaneously through a copper rod from a hot reservoir 650 K to a cold reservoir at 350 K. Determine
the amount by which this irreversible process changes the entropy of the universe, assuming that no other changes occur.
First blank is for the numeric value. The second blank is for the units, putting a space between all characters.
s = [blank_start]1.6[blank_end] [blank_start]J / K[blank_end]