Functions/GenXdev.Helpers.Physics/Get-FreeFallDistance.cs
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// ################################################################################
// Part of PowerShell module : GenXdev.Helpers.Physics // Original cmdlet filename : Get-FreeFallDistance.cs // Original author : René Vaessen / GenXdev // Version : 1.304.2025 // ################################################################################ // 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 distance 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. /// </para> /// /// <para type="description"> /// PARAMETERS /// </para> /// /// <para type="description"> /// -DurationInSeconds <double><br/> /// The time duration of the fall in seconds.<br/> /// - <b>Position</b>: 0<br/> /// - <b>Mandatory</b>: true<br/> /// </para> /// /// <para type="description"> /// -TerminalVelocityInMetersPerSecond <double><br/> /// The terminal velocity in meters per second. Defaults to 53 m/s.<br/> /// - <b>Position</b>: 1<br/> /// - <b>Default</b>: 53<br/> /// </para> /// /// <para type="description"> /// -GravityInMetersPerSecondSquared <double><br/> /// The acceleration due to gravity in m/s². Defaults to 9.81.<br/> /// - <b>Position</b>: 2<br/> /// - <b>Default</b>: 9.81<br/> /// </para> /// /// <para type="description"> /// -As <string><br/> /// The unit for the output distance. Defaults to 'meters'.<br/> /// - <b>Position</b>: 3<br/> /// - <b>Default</b>: meters<br/> /// - <b>Valid values</b>: meters, kilometers, centimeters, millimeters, feet, inches, miles, yards<br/> /// </para> /// /// <example> /// <para>Calculates the distance fallen in 10 seconds in feet.</para> /// <para>Detailed explanation of the example.</para> /// <code> /// Get-FreeFallDistance -DurationInSeconds 10 -TerminalVelocityInMetersPerSecond 53 -As "feet" /// </code> /// </example> /// /// <example> /// <para>Calculates the distance in 5 seconds in meters.</para> /// <para>Detailed explanation of the example.</para> /// <code> /// Get-FreeFallDistance 5 /// </code> /// </example> /// </summary> [Cmdlet(VerbsCommon.Get, "FreeFallDistance")] [OutputType(typeof(double))] public class GetFreeFallDistanceCommand : 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) /// </summary> [Parameter( Mandatory = false, Position = 1, HelpMessage = "The terminal velocity in meters per second (default: 53)")] public double TerminalVelocityInMetersPerSecond { get; set; } = 53; /// <summary> /// The acceleration due to gravity in m/s² (default: 9.81) /// </summary> [Parameter( Mandatory = false, Position = 2, HelpMessage = "The acceleration due to gravity in m/s² (default: 9.81)")] public double GravityInMetersPerSecondSquared { get; set; } = 9.81; /// <summary> /// The unit for the output distance /// </summary> [Parameter( Mandatory = false, Position = 3, HelpMessage = "The unit for the output distance")] [ValidateSet("meters", "kilometers", "centimeters", "millimeters", "feet", "inches", "miles", "yards")] public string As { get; set; } = "meters"; private double time; private double distance; private double velocity; /// <summary> /// Begin processing - initialization logic /// </summary> protected override void BeginProcessing() { // set up numerical integration parameters // initialize variables time = 0; distance = 0; velocity = 0; WriteVerbose( "Starting free fall distance calculation for " + DurationInSeconds + " seconds " + "with terminal velocity " + TerminalVelocityInMetersPerSecond + " m/s"); } /// <summary> /// Process record - main cmdlet logic /// </summary> protected override void ProcessRecord() { double dt = 0.01; while (time < DurationInSeconds) { // cap velocity at terminal if (velocity >= TerminalVelocityInMetersPerSecond) { velocity = TerminalVelocityInMetersPerSecond; } else { velocity += GravityInMetersPerSecondSquared * dt; } // accumulate distance distance += velocity * dt; time += dt; if (time > 1000) { throw new Exception("Calculation timeout exceeded"); } } WriteVerbose("Calculated distance: " + distance + " meters"); } /// <summary> /// End processing - cleanup logic /// </summary> protected override void EndProcessing() { // convert to desired unit var scriptBlock = ScriptBlock.Create(@" param($Value, $FromUnit, $ToUnit) GenXdev.Helpers\Convert-PhysicsUnit -Value $Value -FromUnit $FromUnit -ToUnit $ToUnit "); var result = scriptBlock.Invoke(distance, "meters", As); WriteObject(result[0].BaseObject); } } } |