A-LEVEL PHYSICS: 11.2.2: p-V Diagrams (SaveMyExams) Flashcards
(14 cards)
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 on the piston by the gas (expansion) (+W by gas)
if an external force is applied to the piston, the gas is…
explain work done in this case:
compressed
work is done on the gas by the piston (compression) (-W by gas)
work done 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 (-W by gas)
expanding the gas means…
work is done on the surroundings by the gas (+W by gas)
area under p-V graph:
work done
when a gas is expanded (at constant pressure), work done W by gas is…
positive
when a gas is compressed (at constant pressure) work done W by gas is…
negative
when a gas is ___ (at constant pressure) work done W by gas is positive
expanded
when a gas is ___ (at constant pressure) work done W by gas 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
