Ch 20: The First Law of ThermodynamicsWorksheetSee all chapters
All Chapters
Ch 01: Units & Vectors
Ch 02: 1D Motion (Kinematics)
Ch 03: 2D Motion (Projectile Motion)
Ch 04: Intro to Forces (Dynamics)
Ch 05: Friction, Inclines, Systems
Ch 06: Centripetal Forces & Gravitation
Ch 07: Work & Energy
Ch 08: Conservation of Energy
Ch 09: Momentum & Impulse
Ch 10: Rotational Kinematics
Ch 11: Rotational Inertia & Energy
Ch 12: Torque & Rotational Dynamics
Ch 13: Rotational Equilibrium
Ch 14: Angular Momentum
Ch 15: Periodic Motion (NEW)
Ch 15: Periodic Motion (Oscillations)
Ch 16: Waves & Sound
Ch 17: Fluid Mechanics
Ch 18: Heat and Temperature
Ch 19: Kinetic Theory of Ideal Gasses
Ch 20: The First Law of Thermodynamics
Ch 21: The Second Law of Thermodynamics
Ch 22: Electric Force & Field; Gauss' Law
Ch 23: Electric Potential
Ch 24: Capacitors & Dielectrics
Ch 25: Resistors & DC Circuits
Ch 26: Magnetic Fields and Forces
Ch 27: Sources of Magnetic Field
Ch 28: Induction and Inductance
Ch 29: Alternating Current
Ch 30: Electromagnetic Waves
Ch 31: Geometric Optics
Ch 32: Wave Optics
Ch 34: Special Relativity
Ch 35: Particle-Wave Duality
Ch 36: Atomic Structure
Ch 37: Nuclear Physics
Ch 38: Quantum Mechanics

Concept #1: Introduction to Internal Energy

Concept #2: The Equipartition Theorem and the Internal Energy of Ideal Gasses

Practice: An ideal monoatomic oxygen gas containing 5 x 1025 particles is stored in a closed jar. If the temperature in the jar were initially 27°C, how much heat would you have to add to the gas to raise the temperature to 75°C?

Example #1: Heating a Gas of Diatomic Nitrogen with Rigid Connections

Additional Problems
The temperature of 6.00 moles of a monatomic ideal gas is increased from 20.0°C to 80.0°C in a constant pressure process. During this process the change in internal energy of the gas is(a) zero(b) 4490 J(c) 1497 J(d) 8980 J(e) 7483 J(f) none of the above answers
Four moles of a monatomic ideal gas undergoes a process during which 700 J of heat flows into the gas. Calculate the work W done by the gas and the change ΔU in internal energy of the gas if the process is isobaric (constant p). Note: the heat capacity of the gas (Cp) equals 5/2R.
(a) Four moles of a monoatomic ideal gas undergoes a process in which the temperature of the gas increases from 300 K to 500 K while the pressure is kept constant at 2.00 x 105 Pa. What is the change in internal energy of the gas? Indicate whether the internal energy increases or decreases.               (b) Four moles of the gas undergoes a process for which the volume is 3.00 m 3 and is kept constant while the pressure decreases from 4500 Pa to 3600 Pa. What is the heat flow Q for this process? Does heat flow into the gas or out of the gas?
9.00 moles of a monatomic ideal gas expands isobarically at 3.00 x 10  5 Pa from an initial volume of 0.300 m3 to a final volume of 0.400 m3. What is the change in the internal energy of the gas? In this process, does the internal energy of the gas increase or decrease?
You add equal amounts of heat to two identical cylinders containing equal amounts of the same ideal gas. Cylinder A is allowed to expand while cylinder B is not. How do the temperature changes of the two cylinders compare? (a) Cylinder A will experience a greater temperature change. (b) Cylinder B will experience a greater temperature change. (c) The two cylinders will experience the same temperature change.
A constant amount of ideal gas undergoes an isochoric process, and as a result, its change in internal energy is –100J. What could be the heat added to the system (Q) and the work done by the system (W) in this process? A. Q = -50 J, W = 50 J B. Q = -100 J, W = 0 C. Q = -100 J, W = 200 J D. Q = 100 J, W = 0