Office hours are 12:30pm-2pm on Tuesday, 1:30-2:30pm on Wednesday, or schedule an appointment.

Grades are posted into the web grades book. Make sure that posted grades coincide with their paper one.

For the first time login use your WM official email as “login” and hit the reset password button. You will get a password shortly via email.

If you have any suggestions or comments, please, let me know.

- Angular momentum of many body system
- Transformation of angular momentum between inertial frames
- Center of mass reference frame for the two-body problem

- Two-body system
- kinetic energy expression
- angular momentum expression
- Lagrangian
- conservation laws
- converting to 1D problem with effective potential energy
- 2nd Kepler’s law and angular momentum conservation
- bounded and unbounded orbits

- Two-body system in attractive 1/r potential
- orbits types
- ellipse
- parabola
- hyperbola

- no go zone

- orbits types
- Two-body system in repulsive 1/r potential
- orbits types
- hyperbola

- orbits types

- Two-body system in attractive 1/r potential
- 3rd Kepler’s law
- same semimajor axes different eccentricities cases
- masses of the stellar objects from orbits parameters

- Simple case of the Virial theorem

- Two-body system in attractive 1/r potential
- speed along the orbit
- orbits transfer
- relative change of orbit parameters and what it leads too (all about alpha)

- Two-body system in attractive 1/r potential
- feather and the stone paradox revisited
- orbits transfer continued
- time to Mars travel
- Hohmann transfer

- Collisions and cross sections
- simple definitions
- probability of scatter
- mean free path
- diffusive motion and travel time
- “immeasurable” cross section and how to connect it to scattering angles

- Collisions and cross sections
- differential cross section

- General theory of scattering
- Rutherford scattering

- Moving from CM to the lab reference frame

- Scattering angle in the lab reference frame
- special cases light, heavy, and equal masses
- transformation of differential cross section

- Non-inertial reference frames

- Non-inertial reference frames
- moving with V(t) and rotating
- fictitious forces

- Non-inertial reference frames
- Examples of problems with fictional forces

- Midterm review

- Non-inertial reference frames
- Tidal forces

- Rigid bodies

- A handle in space
- Pliers in space
- Dzhanibekov himself (in Russian) but it shows the effect for a nut and somewhat spherical object. If you know Russian skip the commentary of talking heads, they are nuts.

- Rigid bodies
- angular momentum
- moments of inertia

- Rigid bodies
- kinetic energy and angular momentum with tensor of inertia
- principal axes
- example: tensor of inertia for a cylinder

- Rigid bodies
- Period of rolling cylinder
- rotational speed with respect to different points of the body
- spinning top and precession

- Rigid bodies
- Euler equations
- Chandler wobble

- Rigid bodies
- discussion of various demo movies
- wobble of the top
- “anti-gravity” wheel
- gyro compass
- top precession
- the tennis racket theorem or intermediate axis theorem or the Dzhanibekov Effect (Эффект Джанибекова)

- discussion of various demo movies

With Russian explanations, but demos are still very nice.

- 1D wave equation
- derivation of the wave equation for a string with tension
- general solution with forward and backward moving waves
- solution for known excitation at time 0 and zero initial speed

- 1D wave equation
- Matlab’s demos
- various possible propagating functions
- superposition
- standing wave

- physical demo with rods
- reflection from fixed and free end

- separation of variables techniques

- Matlab’s demos

- 1D wave equation
- derivation of sound (pressure) wave
- full derivation of wave (sound) speed for gases

- Chaos

- Special relativity
- Lorentz transformation via Voigt transformation preserving wave equation

See assignment in the hw01.pdf. Submission deadline is Thursday 09/08 at 11am.

See assignment in the hw02.pdf. Submission deadline is Thursday 09/14 at 11am.

See assignment in the hw03.pdf. Submission deadline is Thursday 09/21 at 11am.

Read chapter 14. Get ready for the first midterm on Thursday 09/28

Read chapter 14. Pay attention to the differential cross section definition and derivation.

Read chapter 14.

See assignment in the hw06.pdf. Submission deadline is Thursday 10/12 at 11am.

See assignment in the hw07.pdf. Submission deadline is Thursday 10/19 at 11am.

Read chapter 9. Get ready for the first midterm on **Tuesday** 11/24

See assignment in the hw09.pdf. Submission deadline is Thursday 11/02 at 11am.

Read chapter 9 about tides, we will go over it on Tuesday. Come with questions.

See assignment in the hw10.pdf. Submission deadline is Thursday 11/09 at 11am.

The problem 3 is reworded. Hopefully it is easier to read now.

See assignment in the hw11.pdf. Submission deadline is Thursday 11/16 at 11am.

In class I distributed a certain toy. Explain why it prefers a certain spinning direction and refuses to spin in the opposite direction.

Submission deadline is Tuesday 11/28 at 11am.

Update for the problem 2. The top is precessing in the Earth gravitational field.

See assignment in the hw12.pdf. Submission deadline is Thursday 11/30 at 11am.

See assignment in the hw13.pdf. Submission deadline is Thursday 12/07 at 11am.