Work
Work
Energy transferred due to force applied on the system.
+ W: Work energy transferred into the system.
− W: Work energy transferred out of the system into the surrounding.
Mechanical Work
W = Fs cosθ
F: Force applied on the body
s: Displacement of the body (Δx)
θ: Angle between force vector and displacement vector
Pressure Volume Work for Gases
Won = −Wby
Won: Work done on the gas (Compression)
Wby: Work done by the gas (Expansion)
Work done on the Gas by Constant Pressure
W = − PΔV
W: Work done on the gas
P: External pressure applied on the gas
V: Volume of the gas
ΔV: Vfinal − Vinitial
For expansion: W is −ve   ∵ ΔV > 0
For compression: W is +ve   ∵ ΔV < 0
Work done on the Gas
W = − ∫ P dV
Work done on Ideal Gas
W = − nRΔT   ∵ PΔV = nRΔT
n: Number of moles of gas in a closed system
R: Universal Gas Constant = 8.3145 J/mol·K   OR   0.08205 L·atm/mol·K
T: Temperature