The Ammunition

• The Round
• Components

Ballistics

• Acceleration in the Gun Tube
• Muzzle Exit
• External Ballistics

Perforation of Finite Targets

• Penetration Process
• Perforation Limit
• Governing Parameters
• Working Length
• Perforation Equation

Penetration in Semi-Infinite Targets

• Semi-infinite Targets
• Penetration Equation

Penetration and Perforation Calculations

• The Calculator

Applications

• Optimum Velocity
• Max. Perforation with a given Gun System

Covid-19 Case Numbers - Similarity with Penetration

• General Equation
• Case Numbers in Switzerland

Papers

• Download

 

    Covid-19 Case Numbers - Equation

The trend of the sum of all positively tested people over the days is comparable to the penetration of long rods as a function of increasing impact velocity in armored steel:

The first part of the curve is exponential. After a point of inflection, the curve flattens and approaches a limit value asymptotically.

y = cumulative total of cases    x = days after first case

The parameters a, b and n can be fitted from the sums of all positively tested people over the days. The condition is that the point of inflection has been passed. The first derivative of the general equation yields in case of covid-19 to the sum of the daily cases and in case of long rods to the growth rate of the penetration depth.

The fit values a, b and n can be used to predict the sum of all positively tested people over the days as well as the daily cases.

Numerical examples are given in Case Numbers in Switzerland.