Physics I: Classical Mechanics

Video Lectures

Displaying all 35 video lectures.
I. Kinematics
Lecture 1
Measurements of Space and Time
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Measurements of Space and Time
This lecture is about units, dimensions, measurements and associated uncertainties, dimensional analysis, and scaling arguments.
Lecture 2
Speed, Velocity and Acceleration
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Speed, Velocity and Acceleration
This lecture is an introduction to kinematics which ultimately leads (in Lecture 4) to trajectories in 3 dimensions.
Lecture 3
Vectors
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Vectors
This lecture is about units, dimensions, measurements and associated uncertainties, dimensional analysis, and scaling arguments.
Lecture 4
3D Kinematics: The Motion of Projectiles
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3D Kinematics: The Motion of Projectiles
In this video lecture, Prof. Walter Lewin lectures about motion of projectiles (if air drag can be ignored). The objects experience a constant vertical acceleration due to the acceleration of gravity (see also Lecture 12).
Lecture 5
Circular Motion
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Circular Motion
In this video lecture, Prof. Walter Lewin teaches about circular motion, centrifuges moving, reference frames and perceived gravity.
Lecture 6
Newton's Three Laws
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Newton's Three Laws
In this video lecture, Prof. Walter Lewin lectures on Newton's First (inertia), Second (F=ma) and Third (action=-reaction) Laws.
Lecture 7
Weight and Weightlessness
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Weight and Weightlessness
In this video lecture, Prof. Walter Lewin explores weight, perceived gravity, weightlessness, free fall, zero perceived gravity in orbit.
Lecture 8
Frictional Forces
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Frictional Forces
In this video lecture, Prof. Walter Lewin lectures exclusively with frictional forces.
Lecture 9
Exam Review
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Exam Review
In this video lecture, Prof. Walter Lewin reviews selected topics previously covered in lectures 1 through 5.
Lecture 10
Hooke's Law and Simple Harmonic Motion
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Hooke's Law and Simple Harmonic Motion
In this video lecture, Prof. Walter Lewin begins his lecture covering topics like the restoring force of a spring (Hooke's Law) which leads to an equation of motion that is characteristic of a simple harmonic oscillator (SHO). Using the small angle approximation, a similar expression is reached for a pendulum.
II. Work and Energy
Lecture 11
Work and Mechanical Energy
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Work and Mechanical Energy
In this video lecture, Prof. Walter Lewin introduces concepts such as work, conservative forces, potential energy, kinetic energy, mechanical energy and Newton's law of universal gravitation.
Lecture 12
Resistive Forces
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Resistive Forces
In this video lecture, Prof. Walter Lewin lectures on resistive forces such as air drag. It includes the viscous (linear in velocity) and pressure (quadratic in velocity) terms. Quantitative demonstrations with balloons and with ball bearings dropped in syrup are shown.
Lecture 13
Conservative Forces and SHO
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Conservative Forces and SHO
In this video lecture, Prof. Walter Lewin lectures on the conservation of mechanical energy which can be used to derive the equation of motion for simple harmonic oscillators (SHO).
Lecture 14
Energy, Power and Satellite Orbits
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Energy, Power and Satellite Orbits
In this video lecture, Prof. Walter Lewin lectures on bound and unbound orbits; escape velocity. Various sources of energy, energy storage, energy conversion, and the world's energy consumption are also discussed.
III. Momentum
Lecture 15
Collisions and the Center of Mass
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Collisions and the Center of Mass
In this video lecture, Prof. Walter Lewin introduces momentum and its conservation during collisions. Kinetic energy can decrease or increase during collisions. When kinetic energy is conserved, we call it an elastic collision.
Lecture 16
Elastic and Inelastic Collisions
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Elastic and Inelastic Collisions
In this video lecture, Prof. Walter Lewin discusses 1D Elastic Collisions, Brain Teasers, Elastic Collisions with a Wall, Center of Mass (CM), Frame of Reference, 1D Inelastic Collision, Internal Energy and a demonstration of Newton's Cradle.
Lecture 17
Change of Momentum, Impulse and Rockets
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Change of Momentum, Impulse and Rockets
In this video lecture, Prof. Walter Lewin lectures on the momentum of individual objects which change in a variety of ways.
Lecture 18
Exam Review
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Exam Review
In this video lecture, Prof. Walter Lewin gives an exam review.
IV. Celestial Mechanics
Lecture 19
Rotational Kinetic Energy
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Rotational Kinetic Energy
In this video lecture, Prof. Walter Lewin lectures on Rotating Rigid Bodies, Moments of Inertia, Parallel Axis and Perpendicular Axis Theorem. The moment of inertia for a rigid body around an axis of rotation is introduced, and related to its rotational kinetic energy. Flywheels can be used to store energy. Planets and stars have spin rotational kinetic energy, and the Crab Nebula pulsar is presented as a spectacular example.
Lecture 20
Angular Momentum
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Angular Momentum
In this video lecture, Prof. Walter Lewin introduces Angular momentum (a vector). The rate of change of angular momentum is related to the torque (also a vector). In the absence of an external torque, angular momentum is conserved. Spin angular momentum (of planets, stars, neutron stars) is also discussed.
Lecture 21
Torques and Oscillating Bodies
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Torques and Oscillating Bodies
In this video lecture, Prof. Walter Lewin discusses how in the absence of a net external torque on an object, angular momentum is conserved. He also discusses when an object oscillates about an axis of rotation, and how there is a variable restoring torque acting on the object.
Lecture 22
Kepler's Laws and Elliptical Orbits
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Kepler's Laws and Elliptical Orbits
In this video lecture, Prof. Walter Lewin lectures on Kepler's Laws, Elliptical Orbits, Change of Orbits, and the famous passing of a Ham Sandwich. Kepler's three Laws summarize the motion of the planets in our solar system. Following Newton's law of universal gravitation, the conservation of angular momentum and mechanical energy allow us to calculate the semimajor axis of the elliptical orbits, the orbital period and other orbital parameters. All we have to know is one position and the associated velocity of a planet and the entire orbit follows.
Lecture 23
Doppler Shift and Stellar Dynamics
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Doppler Shift and Stellar Dynamics
In this video lecture, Prof. Walter Lewin lectures on the Doppler Effect, Binary Stars, Neutron Stars and Black Holes. Doppler shift is introduced with sound waves, then extended to electromagnetic waves (radiation). The Doppler shift of stellar spectral lines and/or pulsar frequencies provides a measure of the line-of-sight (so-called radial) velocity of the source relative to the observer. Combined with Newton's law of universal gravitation, this can lead to the orbital parameters and the mass of both stars in a binary star system.
Lecture 24
Rolling Motion & Gyroscopes
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Rolling Motion & Gyroscopes
In this video lecture, Prof. Walter Lewin lectures on Rolling Motion and Gyroscopes. This material is Very Non-intuitive.
V. Solid Mechanics
Lecture 25
Static Equilibrium
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Static Equilibrium
In this video lecture, Prof. Walter Lewin lectures on Static Equilibrium, Stability and Rope Walkers. Static equilibrium is only achieved when the net external force AND net external torque on an object are both zero.
Lecture 26
Elasticity of Materials
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Elasticity of Materials
In this video lecture, Prof. Walter Lewin discusses Elasticity and Young's Modulus. The fractional length deformation of a material (the strain) depends on the force per unit area (the stress). The stress vs. strain dependence is described conceptually, then explored empirically.
VI. Fluid Mechanics
Lecture 27
Pressure in a Static Fluid
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Pressure in a Static Fluid
In this video lecture, Prof. Walter Lewin discusses concepts such as gases and incompressible liquids, Pascal's Principle, hydrostatic and barometric pressure.
Lecture 28
Buoyant Force and Bernoulli's Equation
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Buoyant Force and Bernoulli's Equation
In this video lecture, Prof. Walter Lewin discusses concepts such as Hydrostatics, Archimedes' Principle, Fluid Dynamics, factors which make a boat float, and Bernoulli's Equation.
Lecture 29
Exam Review
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Exam Review
In this video lecture, Prof. Walter Lewin reviews selected concepts previously covered in lectures 16 through 24.
Lecture 30
Other Oscillating Systems
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Other Oscillating Systems
In this video lecture, Prof. Walter Lewin lectures on the simple harmonic oscillations (SHO) of suspended solid bodies which are related to their geometry. He also discusses how torsional pendulum oscillates in the horizontal plane, and the SHO does NOT depend on the small angle approximation.
Lecture 31
Forced Oscillations and Resonance
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Forced Oscillations and Resonance
In this video lecture, Prof. Walter Lewin lectures on systems consisting of pendulums and springs and how they can freely oscillate at their natural frequencies (also called normal modes). He also discusses when we expose a system to a wide spectrum of frequencies, the response will be very large at the normal mode frequencies (resonances) of that system. Examples include musical instruments (standing waves on violin strings and pressure waves in wind instruments), and torsional standing waves on a bridge driven by strong winds.
VII. Thermal Physics
Lecture 32
Heat, Conductivity and Thermal Expansion
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Heat, Conductivity and Thermal Expansion
In this video lecture, Prof. Walter Lewin discusses how heat raises the temperature, and usually the volume of the material that absorbs the heat. He also lectures on the linear and cubical thermal expansion coefficients of metals (including mercury), which are described and demonstrated. Ice is also discussed as a special case.
Lecture 33
Kinetic Gas Theory & Phases
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Kinetic Gas Theory & Phases
In this video lecture, Prof. Walter Lewin introduces the ideal-gas law and the rate of momentum transfer from the gas molecules to the vessel walls, which is related to pressure. The concepts of phase diagrams and phase transitions are also introduced, and they are explored with fire extinguishers, boiling water, and cooled balloons filled with air. The ideal-gas law holds (approximately) when you have only gas; it doesn't hold whenever there is any liquid present.
VIII. Modern Physics
Lecture 34
The Wonderful Quantum World
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The Wonderful Quantum World
In this video lecture, Prof. Walter Lewin discusses Classical Mechanics, and in spite of all of its impressive predictive power, fails to explain many microscopic behaviors. This led to the development of Quantum Mechanics, where electrons orbit nuclei in discrete energy levels, light can behave as a particle, and particles behave as waves. The location of microscopic particles can only be expressed in terms of probabilities. Heisenberg's uncertainty principle is also discussed and demonstrated.
Lecture 35
X-ray Astronomy and Astrophysics
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X-ray Astronomy and Astrophysics
In this video lecture, Prof. Walter Lewin talks about some of the highlights from his early days at MIT. It began with balloon flights at very high altitude to make observations of the stars in X-rays. This led to discoveries of X-ray flaring events and a periodic X-ray source (GX 1+4). In the seventies and eighties he made important contributions to our understanding of X-ray bursts (thermo-nuclear fusion episodes on neutron stars).