cpd_2022_energy/lib/provider/energy_model.dart

import 'package:flutter/material.dart';

class EnergyModel with ChangeNotifier {
  final double weightForce = 9.81;
  final double _waterStartTemp = 20.0;
  final double _waterEndTemp = 100.0;
  final double _waterHeatCapacity = 4.183;
  final double _ironStartTemp = 20.0;
  final double _ironEndTemp = 700.0;
  final double _ironHeatCapacity = 0.444;

  double heightStart = 0.0;
  double heightEnd = 0.0;
  double velocityStart = 0.0;
  double velocityEnd = 0.0;
  double weight = 0.0;

  double totalEnergy = 0.0;
  double boilingWaterAmount = 0.0;
  double annealingIronAmount = 0.0;

  double calcPotentialEnergy(m, g, h) {
    return m * g * h;
  }

  double calcPotentialEnergyBetweenTwoPointsInJoule(
      heightStart, heightEnd, weight) {
    return calcPotentialEnergy(weight, weightForce, heightStart) -
        calcPotentialEnergy(weight, weightForce, heightEnd);
  }

  double calcKineticEnergy(m, v) {
    return (m * v * v) / 2.0;
  }

  double calcKineticEnergyBetweenTwoPointsInJoule(
      velocityStart, velocityEnd, weight) {
    return calcKineticEnergy(weight, velocityEnd) -
        calcKineticEnergy(weight, velocityStart);
  }

  void calcBoilingWaterAmount() {
    boilingWaterAmount = (totalEnergy /
        (_waterHeatCapacity * (_waterEndTemp - _waterStartTemp)));
  }

  void calcIronAnnealingAmount() {
    annealingIronAmount =
        (totalEnergy / (_ironHeatCapacity * (_ironEndTemp - _ironStartTemp)));
  }

  void calcTotalEnergyInKiloJoule() {
    totalEnergy = (calcKineticEnergyBetweenTwoPointsInJoule(velocityStart, velocityEnd, weight) +
            calcPotentialEnergyBetweenTwoPointsInJoule(heightStart, heightEnd, weight))
        /1000;
  }

  void calc() {
    calcTotalEnergyInKiloJoule();
    calcBoilingWaterAmount();
    calcIronAnnealingAmount();
    notifyListeners();
  }
}