class Vehicle { public $color; function drive() { echo "Driving..."; } } class Car extends Vehicle { public $numWheels; public $model; function accelerate() { echo "Accelerating..."; } } $car1 = new Car; $car1->color = "red"; $car1->numWheels = 4; $car1->model = "sedan"; $car1->drive(); // outputs "Driving..." $car1->accelerate(); // outputs "Accelerating..."This code creates a parent class called "Vehicle" with a property called "color" and a method called "drive()". It also creates a child class called "Car" with additional properties called "numWheels" and "model", and a method called "accelerate()". An instance of the Car class is then created and assigned values for its properties. The drive() and accelerate() methods are then called on the instance, which outputs the respective messages. This code does not require any particular package library, as it only uses built-in PHP functionality.