Walter Lewin

Channel | updated October 11, 2012

Walter Lewin, MIT professor emeritus of physics, has been viewed millions of times on sites like OpenCourseWare, YouTube, and beyond. His introductory physics courses explain the fundamentals, with Lewin often as the test subject. Over the years, Lewin has given more than 800 lectures in Room 26-100.

10: Hooke's Law, Simple Harmonic Oscillator

Topics covered: Concepts covered in this lecture begin with 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 ...

11: Work, Energy, and Universal Gravitation

Topics covered: The concepts introduced are: work, conservative forces, potential energy, kinetic energy, mechanical energy, and Newton's law of universal gravitation. Instructor/speaker: Prof. Walter Lewin Date recorded: October 4, 1999

12: Resistive Forces

Topics covered: This lecture covers 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. Instructor/speaker: Prof. Walter Lewin ...

13: Equation of Motion for Simple Harmonic Oscillators

Topics covered: The conservation of mechanical energy can be used to derive the equation of motion for simple harmonic oscillators (SHO). Instructor/speaker: Prof. Walter Lewin Date recorded: October 8, 1999

14: Orbits and Escape Velocity

Topics covered: Bound and unbound orbits; escape velocity. Various sources of energy, energy storage, energy conversion, and the world's energy consumption are discussed. Instructor/speaker: Prof. Walter Lewin Date recorded: October 13, 1999

15: Momentum and its Conservation

Topics covered: Momentum and its conservation during collisions is introduced. Kinetic energy can decrease or increase during collisions. When kinetic energy is conserved, we call it an elastic collision. Instructor/speaker: Prof. Walter Lewin Date recorded: October 15, 1999

16: Elastic and Inelastic Collisions

Topics covered: Elastic and Inelastic Collisions Instructor/speaker: Prof. Walter Lewin Date recorded: October 18, 1999

17: Momentum of Individual Objects

Topics covered: The momentum of individual objects can change in a variety of ways. Demonstration of impulse and impact time courtesy of Dr. Peter Dourmashkin, MIT. Instructor/speaker: Prof. Walter Lewin Date recorded: October 20, 1999

18: Review of Lectures 6 through 15

Topics covered: This lecture reviews selected concepts previously covered in lectures 6 through 15. Instructor/speaker: Prof. Walter Lewin Date recorded: October 22, 1999

19: Rotating Rigid Bodies, Inertia, and Axis Theorems

Topics covered: 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 ...

20: Angular Momentum

Topics covered: Angular momentum (a vector) is introduced. 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. ...

21: Torque

Topics covered: In the absence of a net external torque on an object, angular momentum is conserved. When an object oscillates about an axis of rotation, there is a variable restoring torque acting on the object. Instructor/speaker: Prof. Walter Lewin Date recorded: November 1, 1999

22: Kepler's Laws, Elliptical Orbits, and Change of Orbits

Topics covered: 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 ...

23: Doppler Effect, Binary Stars, Neutron Stars and Black ...

23: Doppler Effect, Binary Stars, Neutron Stars and Black Holes

Topics covered: 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 ...

24: Rolling Motion, Gyroscopes

Topics covered: Rolling Motion, Gyroscopes, Very Non-intuitive. Instructor/speaker: Prof. Walter Lewin Date recorded: November 8, 1999

25: Static Equilibrium, Stability, Rope Walker

Topics covered: Static Equilibrium, Stability, Rope Walker. Static equilibrium is only achieved when the net external force AND net external torque on an object are both zero. Instructor/speaker: Prof. Walter Lewin Date recorded: November 10, 1999

26: Elasticity and Young's Modulus

Topics covered: 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. Instructor/speaker: Prof. Walter Lewin Date ...