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Describe how to interpret clockwise versus anticlockwise cycles on a PV graph.
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Clockwise cycles indicate negative work, while anticlockwise cycles indicate positive work.
What are the two main ways of energy exchange discussed in thermodynamics?
Heat and Work.
How does work change when a system expands versus when it compresses?
During expansion, ΔV is positive, and work is negative; during compression, ΔV is negative, and work is positive.
Explain the derivation of the work formula from basic principles.
The work formula is derived as: Force (F) = Pressure (P) × Area (A), Volume Change (ΔV) = A × Δx, therefore Work done (W) = -P_external ΔV.
In terms of PV diagrams, how can work done in thermodynamic processes be visualised?
Work done can be visualised as the area under the curve on a PV diagram.
Calculate work done in a thermodynamic context when given a specific expansion value, such as 0.5 meters.
Requires use of the formula Work = -P_external ΔV and knowledge of external pressure.
How do you calculate work done when pressure is variable?
Use integration: W = -∫(from V1 to V2) P dV.
What future thermodynamic processes were mentioned for further study in relation to work?
Isobaric, Isochoric, Isothermal, and Adiabatic processes.
What information can you derive from the area under a PV curve?
The area under the PV curve represents the work done by the system.
Convert an energy value of 1 atm liter into joules.
1 atm liter is equivalent to 101.3 joules.
Why is work considered a path function and not a state function?
Work is a path function because its value depends on the specific process taken by the system, not just the initial and final states.
What is the formula for work done in a system with constant external pressure?
Work = -P_external ΔV, where P_external is the external pressure and ΔV is the change in volume.
How is the direction of a cycle (clockwise or anticlockwise) determined on a PV graph?
It is determined by the sequence of processes in the cycle and their orientation on the graph.
What is the significance of work in a cyclic process?
In a cyclic process, the work done is not zero and equals the area enclosed by the cycle on a PV diagram.
What mathematic operation is essential in calculating work when dealing with variable pressure?
Integration is essential for calculating work with variable pressure.
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