Thermodynamic Mechanical Work Flashcards
(17 cards)
What types of work exist in thermodynamics?
Mechanical, electrical, capacitive, magnetic, and dielectric.
What is the formula for mechanical work in 1D?
W=∫ FdL
If constant force: W = FΔL
What does a positive value of W indicate in 1D work?
Work is done on the system by the surroundings.
Graphically, how is work represented in 1D?
As the area under the force-extension curve (F–L graph).
What is Atomic Force Microscopy and how does it relate to thermodynamic work?
Atomic Force Microscopy uses a cantilever to measure forces at the nanoscale.
𝑊 = ∫𝐹(𝑧) 𝑑𝑧
How is force determined in AFM?
F=kz, where
𝑘 is the spring constant and 𝑧 is deflection.
What is the formula for mechanical work in 2D with surface tension?
W = ∫ TdA
What is surface tension (𝒯) defined as?
𝑇 = 𝐹 / 𝑤
Force per unit length acting along a membrane.
Give an example where 2D work is relevant.
Emulsions or droplet formation, where surface tension resists area change.
What is the formula for mechanical work in 3D?
W=−∫ PdV
Why is work negative when the system expands?
Because work is done by the system → loss of internal energy.
What is isobaric work in 3D?
W=−PΔV, with constant pressure
What is the work done in an isochoric process?
Zero; since Δ𝑉 = 0, there is no volume change.
Derive work done during isothermal compression of an ideal gas.
W=−nRTln(V1 / V2)
What is the work done during free expansion?
Zero; no pressure is exerted → 𝑊= 0
When is a thermodynamic process considered reversible?
When the system passes through quasi-static equilibrium states and can return without energy exchange.
