diff --git a/1ano/2semestre/poo/src/aula09/ex1/ALDemo.java b/1ano/2semestre/poo/src/aula09/ex1/ALDemo.java
new file mode 100644
index 0000000..ba1b60c
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula09/ex1/ALDemo.java
@@ -0,0 +1,42 @@
+package aula09.ex1;
+
+import aula06.ex1.Person;
+import utils.DateYMD;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+public class ALDemo {
+    public static void main(String[] args) {
+        ArrayList<Integer> c1= new ArrayList<>();
+        for(int i= 10; i<= 100; i+=10) c1.add(i);System.out.println("Size: "+ c1.size());
+
+        for(int i= 0; i< c1.size(); i++)
+            System.out.println("Elemento: "+ c1.get(i));
+
+        ArrayList<String> c2= new ArrayList<>();
+        c2.add("Vento");
+        c2.add("Calor");
+        c2.add("Frio");
+        c2.add("Chuva");
+        System.out.println(c2);
+        Collections.sort(c2);
+        System.out.println(c2);
+        c2.remove("Frio");
+        c2.remove(0);
+        System.out.println(c2);
+
+        Set<Person> c3 = new HashSet<>();
+        c3.add(new Person("Ana", 12345678, new DateYMD(1, 1, 2000)));
+        c3.add(new Person("Joao", 42342289, new DateYMD(1, 1, 2000)));
+        c3.add(new Person("Maria", 12346789, new DateYMD(1, 1, 2000)));
+        c3.add(new Person("Marco", 12356789, new DateYMD(1, 1, 2000)));
+        c3.add(new Person("Ana", 12346789, new DateYMD(1, 1, 2000)));
+
+        for (Person p : c3) {
+            System.out.println(p);
+        }
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula09/ex2/CollectionTester.java b/1ano/2semestre/poo/src/aula09/ex2/CollectionTester.java
new file mode 100644
index 0000000..e860748
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula09/ex2/CollectionTester.java
@@ -0,0 +1,46 @@
+package aula09.ex2;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Iterator;
+
+public class CollectionTester {
+    public static void main(String[] args) {
+        int DIM= 5000;
+        Collection<Integer> col= new ArrayList<>();
+        checkPerformance(col, DIM);
+    }
+
+    private static void checkPerformance(Collection<Integer> col, int DIM) {
+        double start, stop, delta;
+        // Add
+        start = System.nanoTime(); // clock snapshot before
+        for(int i=0; i<DIM; i++)
+            col.add(i);
+        stop = System.nanoTime();  // clock snapshot after
+        delta = (stop-start)/1e6;  // convert to milliseconds
+        System.out.println(col.size()+ ": Add to "+col.getClass().getSimpleName() +" took "+ delta+ "ms");
+
+        // Search
+        start = System.nanoTime(); // clock snapshot before
+        for(int i=0; i<DIM; i++) {
+            int n = (int) (Math.random()*DIM);
+            if(!col.contains(n))
+                System.out.println("Not found???"+n);
+        }
+        stop = System.nanoTime();  // clock snapshot after
+        delta = (stop-start)/1e6;  // convert nanoseconds to milliseconds
+        System.out.println(col.size()+ ": Search to "+ col.getClass().getSimpleName() +" took "+ delta+ "ms");
+
+        // Remove
+        start = System.nanoTime(); // clock snapshot before
+        Iterator<Integer> iterator = col.iterator();
+        while(iterator.hasNext()) {
+            iterator.next();
+            iterator.remove();
+        }
+        stop = System.nanoTime();  // clock snapshot after
+        delta = (stop-start)/1e6;  // convert nanoseconds to milliseconds
+        System.out.println(col.size() + ": Remove from "+ col.getClass().getSimpleName() +" took "+ delta+ "ms");
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula09/ex3/CommercialPlane.java b/1ano/2semestre/poo/src/aula09/ex3/CommercialPlane.java
new file mode 100644
index 0000000..9877124
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula09/ex3/CommercialPlane.java
@@ -0,0 +1,50 @@
+package aula09.ex3;
+
+import java.util.Objects;
+
+public class CommercialPlane extends Plane {
+    private int numOfCrewMembers;
+
+    public CommercialPlane(String id, String manufacturer, String model, int year, int maxNumOfPassengers, double maxSpeed, int numOfCrewMembers) {
+        super(id, manufacturer, model, year, maxNumOfPassengers, maxSpeed);
+        this.numOfCrewMembers = numOfCrewMembers;
+    }
+
+    public int getNumOfCrewMembers() {
+        return this.numOfCrewMembers;
+    }
+
+    public void setNumOfCrewMembers(int numOfCrewMembers) {
+        this.numOfCrewMembers = numOfCrewMembers;
+    }
+
+    public String getPlaneType() {
+        return "Commercial";
+    }
+
+    @Override
+    public String toString() {
+        return "CommercialPlane {" +
+                "\n\tid='" + super.getId() + '\'' +
+                ",\n\tmanufacturer='" + super.getManufacturer() + '\'' +
+                ",\n\tmodel='" + super.getModel() + '\'' +
+                ",\n\tproductionYear=" + super.getProductionYear() +
+                ",\n\tmaxPassengers=" + super.getMaxPassengers() +
+                ",\n\tmaxSpeed=" + super.getMaxSpeed() +
+                ",\n\tnumOfCrewMembers=" + this.getNumOfCrewMembers() +
+                ",\n}";
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof CommercialPlane plane)) return false;
+        if (!super.equals(o)) return false;
+        return this.getNumOfCrewMembers() == plane.getNumOfCrewMembers();
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), this.getNumOfCrewMembers());
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula09/ex3/MilitaryPlane.java b/1ano/2semestre/poo/src/aula09/ex3/MilitaryPlane.java
new file mode 100644
index 0000000..38c6eb7
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula09/ex3/MilitaryPlane.java
@@ -0,0 +1,50 @@
+package aula09.ex3;
+
+import java.util.Objects;
+
+public class MilitaryPlane extends Plane {
+    private int numMissiles;
+
+    public MilitaryPlane(String id, String manufacturer, String model, int year, int maxPassengers, double maxSpeed, int numMissiles) {
+        super(id, manufacturer, model, year, maxPassengers, maxSpeed);
+        this.numMissiles = numMissiles;
+    }
+
+    public int getNumMissiles() {
+        return this.numMissiles;
+    }
+
+    public void setNumMissiles(int numMissiles) {
+        this.numMissiles = numMissiles;
+    }
+
+    public String getPlaneType() {
+        return "Military";
+    }
+
+    @Override
+    public String toString() {
+        return "MilitaryPlane {" +
+                "\n\tid='" + super.getId() + '\'' +
+                ",\n\tmanufacturer='" + super.getManufacturer() + '\'' +
+                ",\n\tmodel='" + super.getModel() + '\'' +
+                ",\n\tproductionYear=" + super.getProductionYear() +
+                ",\n\tmaxPassengers=" + super.getMaxPassengers() +
+                ",\n\tmaxSpeed=" + super.getMaxSpeed() +
+                ",\n\tnumMissiles=" + this.getNumMissiles() +
+                ",\n}";
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof MilitaryPlane plane)) return false;
+        if (!super.equals(o)) return false;
+        return this.getNumMissiles() == plane.getNumMissiles();
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), this.getNumMissiles());
+    }
+}
\ No newline at end of file
diff --git a/1ano/2semestre/poo/src/aula09/ex3/Plane.java b/1ano/2semestre/poo/src/aula09/ex3/Plane.java
new file mode 100644
index 0000000..143348f
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula09/ex3/Plane.java
@@ -0,0 +1,90 @@
+package aula09.ex3;
+
+import java.util.Objects;
+
+public class Plane {
+    private final String id;
+    private String manufacturer;
+    private String model;
+    private int productionYear;
+    private int maxPassengers;
+    private double maxSpeed;
+
+    public Plane(String id, String manufacturer, String model, int productionYear, int maxPassengers, double maxSpeed) {
+        this.id = id;
+        this.manufacturer = manufacturer;
+        this.model = model;
+        this.productionYear = productionYear;
+        this.maxPassengers = maxPassengers;
+        this.maxSpeed = maxSpeed;
+    }
+
+
+    public String getId() {
+        return id;
+    }
+
+    public String getManufacturer() {
+        return manufacturer;
+    }
+
+    public void setManufacturer(String manufacturer) {
+        this.manufacturer = manufacturer;
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public void setModel(String model) {
+        this.model = model;
+    }
+
+    public int getProductionYear() {
+        return productionYear;
+    }
+
+    public void setProductionYear(int productionYear) {
+        this.productionYear = productionYear;
+    }
+
+    public int getMaxPassengers() {
+        return maxPassengers;
+    }
+
+    public void setMaxPassengers(int maxPassengers) {
+        this.maxPassengers = maxPassengers;
+    }
+
+    public double getMaxSpeed() {
+        return maxSpeed;
+    }
+
+    public void setMaxSpeed(double maxSpeed) {
+        this.maxSpeed = maxSpeed;
+    }
+
+    @Override
+    public String toString() {
+        return "Plane {" +
+                "\n\tid='" + id + '\'' +
+                ",\n\tmanufacturer='" + manufacturer + '\'' +
+                ",\n\tmodel='" + model + '\'' +
+                ",\n\tproductionYear=" + productionYear +
+                ",\n\tmaxPassengers=" + maxPassengers +
+                ",\n\tmaxSpeed=" + maxSpeed +
+                ",\n}";
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof Plane plane)) return false;
+        return this.getProductionYear() == plane.getProductionYear() && this.getMaxPassengers() == plane.getMaxPassengers() && Double.compare(plane.getMaxSpeed(), this.getMaxSpeed()) == 0 && Objects.equals(this.getId(), plane.getId()) && Objects.equals(this.getManufacturer(), plane.getManufacturer()) && Objects.equals(this.getModel(), plane.getModel());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(this.getId(), this.getManufacturer(), this.getModel(), this.getProductionYear(), this.getMaxPassengers(), this.getMaxSpeed());
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula09/ex3/PlaneManager.java b/1ano/2semestre/poo/src/aula09/ex3/PlaneManager.java
new file mode 100644
index 0000000..10a6d1c
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula09/ex3/PlaneManager.java
@@ -0,0 +1,76 @@
+package aula09.ex3;
+
+import java.util.*;
+
+public class PlaneManager {
+    private final LinkedList<Plane> planes = new LinkedList<>();
+
+    public void addPlane(Plane plane) {
+        planes.add(plane);
+    }
+
+    public void removePlane(String id) {
+        for (Plane plane : planes) {
+            if (plane.getId().equals(id)) {
+                planes.remove(plane);
+                return;
+            }
+        }
+    }
+
+    public Plane searchPlane(String id) {
+        for (Plane plane : planes) {
+            if (plane.getId().equals(id)) {
+                return plane;
+            }
+        }
+        return null;
+    }
+
+    public LinkedList<Plane> getCommercialPlanes() {
+        LinkedList<Plane> commercialPlanes = new LinkedList<>();
+        for (Plane plane : planes) {
+            if (plane instanceof CommercialPlane) {
+                commercialPlanes.add(plane);
+            }
+        }
+        return commercialPlanes;
+    }
+
+    public LinkedList<Plane> getMilitaryPlanes() {
+        LinkedList<Plane> militaryPlanes = new LinkedList<>();
+        for (Plane plane : planes) {
+            if (plane instanceof MilitaryPlane) {
+                militaryPlanes.add(plane);
+            }
+        }
+        return militaryPlanes;
+    }
+
+    public Plane getFastestPlane() {
+        Plane fastestPlane = null;
+        for (Plane plane : planes) {
+            if (fastestPlane == null || plane.getMaxSpeed() > fastestPlane.getMaxSpeed()) {
+                fastestPlane = plane;
+            }
+        }
+        return fastestPlane;
+    }
+
+    public void printAllPlanes() {
+        for (Plane plane : planes) {
+            System.out.println(plane);
+        }
+    }
+
+    public void printAllPlanes(String type) {
+        for (Plane plane : planes) {
+            if (plane instanceof CommercialPlane && type.equals("commercial")) {
+                System.out.println(plane);
+            }
+            else if (plane instanceof MilitaryPlane && type.equals("military")) {
+                System.out.println(plane);
+            }
+        }
+    }
+}
diff --git a/1ano/2semestre/poo/src/aula09/ex3/PlaneTester.java b/1ano/2semestre/poo/src/aula09/ex3/PlaneTester.java
new file mode 100644
index 0000000..31e1f59
--- /dev/null
+++ b/1ano/2semestre/poo/src/aula09/ex3/PlaneTester.java
@@ -0,0 +1,104 @@
+package aula09.ex3;
+
+import java.util.Scanner;
+
+public class PlaneTester {
+    public static void main(String[] args) {
+        PlaneManager planeManager = new PlaneManager();
+        Scanner scanner = new Scanner(System.in);
+        int choice;
+
+        do {
+            System.out.println("\nPlane Fleet Menu:");
+            System.out.println("1. Add a plane to the fleet");
+            System.out.println("2. Remove a plane from the fleet");
+            System.out.println("3. Search for a plane");
+            System.out.println("4. Print summary of all planes in the fleet");
+            System.out.println("5. Print list of all commercial planes in the fleet");
+            System.out.println("6. Print list of all military planes in the fleet");
+            System.out.println("7. Print the fastest plane in the fleet");
+            System.out.println("0. Exit");
+
+            System.out.print("Enter your choice: ");
+            choice = Integer.parseInt(scanner.nextLine());
+
+            switch (choice) {
+                case 1 -> addPlane(planeManager, scanner);
+                case 2 -> removePlane(planeManager, scanner);
+                case 3 -> searchPlane(planeManager, scanner);
+                case 4 -> printAllPlanes(planeManager);
+                case 5 -> printCommercialPlanes(planeManager);
+                case 6 -> printMilitaryPlanes(planeManager);
+                case 7 -> printFastestPlane(planeManager);
+                case 0 -> System.out.println("Exiting program...");
+                default -> System.out.println("Invalid choice. Please try again.");
+            }
+        } while (choice != 0);
+
+        scanner.close();
+    }
+
+    private static void addPlane(PlaneManager planeManager, Scanner scanner) {
+        System.out.print("Enter the plane's ID: ");
+        String id = scanner.nextLine();
+        System.out.print("Enter the plane's manufacturer: ");
+        String manufacturer = scanner.nextLine();
+        System.out.print("Enter the plane's model: ");
+        String model = scanner.nextLine();
+        System.out.print("Enter the plane's year of manufacture: ");
+        int year = Integer.parseInt(scanner.nextLine());
+        System.out.print("Enter the plane's passenger count: ");
+        int passengerCount = Integer.parseInt(scanner.nextLine());
+        System.out.print("Enter the plane's maximum speed: ");
+        int maxSpeed = Integer.parseInt(scanner.nextLine());
+        System.out.print("Enter the plane's type (commercial/military): ");
+        String type = scanner.nextLine();
+        if (type.equals("commercial")) {
+            System.out.print("Enter the plane's crew members count: ");
+            int crewMembersCount = Integer.parseInt(scanner.nextLine());
+            planeManager.addPlane(new CommercialPlane(id, manufacturer, model, year, passengerCount, maxSpeed, crewMembersCount));
+        }
+        else if (type.equals("military")) {
+            System.out.print("Enter the plane's missile count: ");
+            int missileCount = Integer.parseInt(scanner.nextLine());
+            planeManager.addPlane(new MilitaryPlane(id, manufacturer, model, year, passengerCount, maxSpeed, missileCount));
+        }
+    }
+
+    private static void removePlane(PlaneManager planeManager, Scanner scanner) {
+        System.out.print("Enter the plane's ID: ");
+        String id = scanner.nextLine();
+        if (planeManager.searchPlane(id) == null) {
+            System.out.println("Plane not found.");
+            return;
+        }
+        planeManager.removePlane(id);
+    }
+
+    private static void searchPlane(PlaneManager planeManager, Scanner scanner) {
+        System.out.print("Enter the plane's ID: ");
+        String id = scanner.nextLine();
+        Plane plane = planeManager.searchPlane(id);
+        if (plane == null) {
+            System.out.println("Plane not found.");
+            return;
+        }
+        System.out.println(plane);
+    }
+
+    private static void printAllPlanes(PlaneManager planeManager) {
+        planeManager.printAllPlanes();
+    }
+
+    private static void printCommercialPlanes(PlaneManager planeManager) {
+        planeManager.printAllPlanes("commercial");
+    }
+
+    private static void printMilitaryPlanes(PlaneManager planeManager) {
+        planeManager.printAllPlanes("military");
+    }
+
+    private static void printFastestPlane(PlaneManager planeManager) {
+        System.out.print(planeManager.getFastestPlane());
+    }
+}