Functions/GenXdev.Helpers.Physics/Get-FreeFallHeight.cs
|
// ################################################################################
// Part of PowerShell module : GenXdev.Helpers.Physics // Original cmdlet filename : Get-FreeFallHeight.cs // Original author : René Vaessen / GenXdev // Version : 2.0.2025 // ################################################################################ // Copyright (c) René Vaessen / GenXdev // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // ################################################################################ using System; using System.Management.Automation; namespace GenXdev.Helpers.Physics { /// <summary> /// <para type="synopsis"> /// Calculates the height fallen during free fall for a given time duration. /// </para> /// /// <para type="description"> /// This function calculates the distance fallen during free fall using a /// numerical method that accounts for air resistance and terminal velocity. The /// calculation uses small time steps to accurately model the physics of falling /// objects with realistic terminal velocity constraints. /// </para> /// /// PARAMETERS /// /// <para type="description"> /// -DurationInSeconds <double><br/> /// The time duration of the fall in seconds for which to calculate the height.<br/> /// - <b>Position</b>: 0<br/> /// </para> /// /// <para type="description"> /// -TerminalVelocityInMs <double><br/> /// The terminal velocity in meters per second. Defaults to 53 m/s which is the /// typical terminal velocity for a human in free fall.<br/> /// - <b>Position</b>: 1<br/> /// - <b>Default</b>: 53<br/> /// </para> /// /// <para type="description"> /// -As <string><br/> /// The unit for the output height. Defaults to 'meters'.<br/> /// - <b>Position</b>: 2<br/> /// - <b>Default</b>: "meters"<br/> /// </para> /// /// <example> /// <para>Calculates the height fallen in 10 seconds with default human terminal velocity.</para> /// <code>Get-FreeFallHeight -DurationInSeconds 10 -TerminalVelocityInMs 53</code> /// </example> /// /// <example> /// <para>Calculates the height fallen in 5 seconds using positional parameter and default terminal velocity.</para> /// <code>Get-FreeFallHeight 5</code> /// </example> /// /// <example> /// <para>Calculates the height fallen in 10 seconds and returns the result in feet.</para> /// <code>Get-FreeFallHeight -DurationInSeconds 10 -As "feet"</code> /// </example> /// </summary> [Cmdlet(VerbsCommon.Get, "FreeFallHeight")] [OutputType(typeof(double))] public class GetFreeFallHeightCommand : PSGenXdevCmdlet { /// <summary> /// The time duration of the fall in seconds /// </summary> [Parameter( Mandatory = true, Position = 0, HelpMessage = "The time duration of the fall in seconds" )] public double DurationInSeconds { get; set; } /// <summary> /// The terminal velocity in meters per second (default: 53 m/s for human) /// </summary> [Parameter( Mandatory = false, Position = 1, HelpMessage = ("The terminal velocity in meters per second " + "(default: 53 m/s for human)") )] public double TerminalVelocityInMs { get; set; } = 53; /// <summary> /// The unit for the output height /// </summary> [Parameter( Mandatory = false, Position = 2, HelpMessage = "The unit for the output height" )] [ValidateSet("meters", "kilometers", "centimeters", "millimeters", "feet", "inches", "miles", "yards")] public string As { get; set; } = "meters"; /// <summary> /// Begin processing - initialization logic /// </summary> protected override void BeginProcessing() { WriteVerbose( "Starting free fall calculation for " + DurationInSeconds + " seconds " + "with terminal velocity " + TerminalVelocityInMs + " m/s" ); } /// <summary> /// Process record - main cmdlet logic /// </summary> protected override void ProcessRecord() { // define the acceleration due to gravity in meters per second squared double gravity = 9.81; // set up numerical integration parameters for accurate calculation double dt = 0.01; // initialize time tracking variable double time = 0; // initialize height accumulator double height = 0; // initialize velocity tracker double velocity = 0; // perform numerical integration using small time steps while (time < DurationInSeconds) { // apply air resistance model by capping velocity at terminal velocity if (velocity >= TerminalVelocityInMs) { // maintain constant terminal velocity when reached velocity = TerminalVelocityInMs; } else { // accelerate under gravity when below terminal velocity velocity += gravity * dt; } // calculate distance traveled in this time step height += velocity * dt; // advance time by one step time += dt; // prevent infinite loops with safety timeout if (time > 1000) { WriteError(new ErrorRecord( new Exception("Calculation timeout exceeded 1000 seconds"), "CalculationTimeout", ErrorCategory.OperationTimeout, null )); WriteObject(0.0); return; } } WriteVerbose("Calculated fall height: " + height + " meters"); // convert to desired unit var scriptBlock = ScriptBlock.Create( "param($Value, $FromUnit, $ToUnit) " + "GenXdev.Helpers\\Convert-PhysicsUnit -Value $Value -FromUnit $FromUnit -ToUnit $ToUnit" ); var results = scriptBlock.Invoke(height, "meters", As); double result = (double)((PSObject)results[0]).BaseObject; // return the calculated height as double WriteObject(result); } /// <summary> /// End processing - cleanup logic /// </summary> protected override void EndProcessing() { } } } // ############################################################################### |