# The first law of thermodynamics

Attended Shankersinh Vaghela Bapu Institute of Technology um ms engineering works
18. Aug 2018
1 von 10

### The first law of thermodynamics

• 1. The First Law of Thermodynamics PREPARED BY: MANAN BHATT(17MSE003)
• 2. The First Law of Thermodynamics FIRST LAW OF THERMODYNAMICS → CONSERVATION OF ENERGY:  Energy Can Be Changed From One Form To Another, But It Cannot Be Created Or Destroyed.  The Total Amount Of Energy And Matter In The Universe Remains Constant, Merely Changing From One Form To Another.  Energy Exists In Many Forms, Such As Mechanical Energy, Heat, Light, Chemical Energy, And Electrical Energy.  Energy Is The Ability To Bring About Change Or To Do Work.  Thermodynamics Is The Study Of Energy.
• 3. Surroundings The Boundary Of The System Is Arbitrarily Chosen  The System Can Exchange Mass And Energy Through The Boundary With The Environment.  An Example Of “Closed System” - No Mass Flow- Is The Gas Confined In A Cylinder. The Boundary –In This Case Real Wall- Is Made By The Cylinder And The Piston Walls. System
• 4.  An Isothermal Process Is One Where The Temperature Does Not Change.
• 5.  In Order For An Isothermal Process To Take Place, We Assume The System Is In Contact With A Heat Reservoir.  In General, We Assume That The System Remains In Equilibrium Throughout All Processes.  An Adiabatic Process Is One Where There Is No Heat Flow Into Or Out Of The System.
• 6.  An Isobaric Process Occurs At Constant Pressure; An Isovolumetric One At Constant Volume.  If The Pressure Is Constant, The Work Done Is The Pressure Multiplied By The Change In Volume:
• 7.  For Processes Where The Pressure Varies, The Work Done Is The Area Under The P-V Curve.
• 8.  If We Apply The First Law Of Thermodynamics To The Human Body: We Know That The Body Can Do Work. If The Internal Energy Is Not To Drop, There Must Be Energy Coming In. It Isn’t In The Form Of Heat; The Body Loses Heat Rather Than Absorbing It. Rather, It Is The Chemical Potential Energy Stored In Foods.
• 9.  The Metabolic Rate Is The Rate At Which Internal Energy Is Transformed In The Body. For 65kg person
• 10. THANK YOU