A-LEVEL PHYSICS: 11.2.2: p-V Diagrams (SaveMyExams) Flashcards
when a gas expands, …
it does work on its surroundings
by exerting pressure on the walls of the container
for a gas inside a piston, the force exerted by the gas…
explain the work done in this case:
pushes the piston outwards
work is done by the gas on the piston (expansion)
if an external force is applied to the piston, the gas is…
explain work done in this case:
compressed
work is done by the piston on the gas (compression)
work down when the volume of gas changes at constant pressure is:
W = pΔV
p-V diagrams are often used to represent changes in the ___ of a ___ in thermodynamic processes
state of a gas
compressing the gas means…
work is done on the gas by the surroundings
expanding the gas means…
work is done by the gas on the surroundings
area under p-V graph:
work done
when a gas is expanded (at constant pressure), work done W is…
positive
when a gas is compressed (at constant pressure) work done W is…
negative
when a gas is ___ (at constant pressure) work done W is positive
expanded
when a gas is ___ (at constant pressure) work done W is negative
compressed
when both the volume and pressure of gas changes, work done can be determined from…
area under p-V graph
in the context of engines, p-V diagrams are referred to as…
indicator diagrams
