# model

#### A Basic Planetary System – video preview

Since not everybody has Excel and more and more people are on the dumbed down new versions (2007 and 2010) I am presenting these previews to give the readers a feel of the real speed and feel of some of the models in older Excel versions (in this case 2003). This preview refers to an older model.

#### Casual Introduction to Numerical Methods – spring-mass-damper system model – part#5

In this tutorial, most of the calculations for the numerical simulation a SMD (spring-mas-damper) system will be consolidated into a single formula, the coordinate formula. In this case, in order to calculate the coordinate at the end of a any time step, we will need just the coordinates from the previous two time steps and of course the input parameters (constants). These input parameters are: mass, damping ratio, spring constant and time…

#### Casual Introduction to Numerical Methods – spring-mass-damper system model – part#4

This tutorial explains the principles to generating animation for the spring-mass-damper system analyzed in the previous presentations.

#### 2D Projectile Motion Tutorial #5

This is the next in a series of projectile motion tutorials for creating 2D trajectory models using numerical analysis of projectile dynamics (including aerodynamic drag). The trajectory formulas were derived in the previous tutorial. This post describes the Excel implementation (spreadsheet formulas, VBA code, buttons and charts).

#### 2D Projectile Motion Tutorial #4

This tutorial derives the formulas of a projectile model taking into account the aerodynamic drag. A finite differences numerical method is used. Though fairly easy to apply and understand, this type of methods can solve much more complex problems than the high-school type approach shown in the previous tutorials. An Excel model will be implemented in the next section.

#### 2D Projectile Motion Tutorial #3

Now that we have a simple animated projectile motion (previous tutorial) let’s try to add on the chart the three instantaneous speed vectors associated with the projectile. These speed vectors are: the horizontal speed, vertical speed and the total speed vector. The model works in all Excel versions but in 2007 it’s painfully slow.

#### 2D Projectile Motion Tutorial #2

This part of the tutorial shows you how to animate the model created in the first part. Since it is addressed to beginners, this part of the tutorial will show you in detail how to create buttons and the associated macros for the input data interface and it will also show you how to animate the flight of the projectile and explain the VBA macro behind the animation.

#### 2D Projectile Motion Tutorial #1

This part of the tutorial will show you how to create the simplest possible projectile motion model using standard kinematic formulas from the first year of high school. The variable parameters of the model will be: initial height, initial speed and initial angle and time step. “g” – the gravitational constant will be set at 9.81 m/s^2. This model is a static one and it will be animated in the following…

#### 2D Projectile Motion Model #1 – a virtual tactical shooting range

Hi Folks, As a kid was fascinated with high power rifles, sniper rifles, cannons and in general, fast projectiles. As a kid I’ve been brainwashed with all sorts of urban legends about how far an AK 47 or a pistol can shoot or how thick a steel metal plate a bullet can penetrate at various distances. I’ve also watched some documentary about snipers and there were talking about highly bent trajectories, how…

#### Casual Introduction to Numerical Methods – a spring-mass-damper system model – part#3

Here is the third part of a tutorial in both elementary dynamics and numerical methods. It is written at a basic level and it shows you how to set up a dynamic model for numerical solving of simple differential equations. The dynamic model makes use of an infinite loop, which make the calculations advance in time. Instead of a large table with formulas, this time we have a small number of…

#### Casual Introduction to Numerical Methods – a spring-mass-damper system model – part#2

Here is the second part of a tutorial in both elementary dynamics and numerical methods. It is written at a basic level and it shows you how to solve a system of difference equations in an Excel table. It also starts to explain how to animate the model.

#### Casual Introduction to Numerical Methods – a spring-mass-damper system model – part#1

Here is the first part of a casual tutorial in both elementary dynamics and numerical methods. It is written at a very basic level and it shows you how to solve a system of difference equations with a pencil and a paper and perhaps a pocket calculator to speed things up.

#### Triple Spring-Mass-Damper System

This is the model of a triple spring-mass-damper system in excel. Recommending this site to your friends would be highly appreciated. Thanks for your support!