# physics

#### Two Lissajous Models – a video preview

This is a video preview for two older models included in this blog, a static model and a dynamic model.

#### Spectral Analysis – a Fourier transform tutorial – part #5

This part of the tutorial demonstrates the Fourier transform operation in a few cases of periodic and aperiodic signals, such as an AM signal, an FM signal, a rectangular nonrepetitive signal and a cardinal sinus signal. The last slide contains an application to the scaling property of the Fourier transform on a nonrepetitive time signal. It actually shows that spreading a signal in the time domain shrinks its spectrum and…

#### Spectral Analysis – a Fourier transform tutorial – part #4

The previous sections explaind the creation of a discrete Fourier transform model in Excel. This section and the following one will use the model to calculate and chart the Fourier transform in several cases of periodic and aperiodic signals.

#### Spectral Analysis – a Fourier transform tutorial – part #3

While the previous sections of the tutorial handled the basic formulas behind building a Fourier model and creating a set of input functions, this section deals with formula implementation on the spreadsheet, the brief VBA code and the charting of the Fourier transform components.

#### A basic 3-body Planetary System

Hi folks, as a continuation to the previous tutorial here is a 3-body planetary model where the solution to the equations is contained in a static form, as a lookup table (I previously called it a “pure spreadsheet solution”). The model is static in the sense that after any parameter is changed, the solution data remains unchanged in a table until a new parameter is updated by the user. The display is dynamic however since an “Offset()” function…

#### How to Model a Basic 2-body Planetary System

Here is a tutorial explaining how to model a two dimensional 2-body planetary system in Excel. It uses the Euler method of integration. The tutorial starts with explaining the simple newtonial laws acting on the two planets. There are essentially just two forces acting on each body at any time: the inertia and the gravitational attraction. During each small time step, from the distance between bodies we can calculate the gravitational…

#### Tutorial – a Static Lissajous Emulator

Hi there, this is a tutorial explaining the construction of a very basic Lissajous emulator in Excel. It’s supposed to be very easy to understand at the high school level. Good luck, George

#### Dynamic Lissajous Emulator

This is a dynamic Lissajous emulator in the sense that the waveform is obtained by combining 2 time varying sinusoidal waves with different frequencies.

#### Static Lissajous Emulators (2D and 3D)

This is a static Lissajous emulator in the sense that the waveform is obtained by combining 2 static sinusoidal waves with different frequencies. As a paranthesis, I will be preparing a dynamic version which will look just like the wave shape seen on a real oscilloscope. The file presented here has two different worksheets, the first one contains a classic 2D Lissajous figure and the second one has a 3D Lissajous pattern obtained from three different…