Final answer:
The rear defroster of a car is a pattern of thin metal strips across the window that enhances visibility by generating heat to remove condensation and frost. It also improves aerodynamics and airflow over the rear of the car.
Step-by-step explanation:
The rear defroster of a car is a pattern of thin metal strips across the window because it enhances visibility. The strips are designed to generate heat when an electric current is passed through them, which helps to remove condensation and frost from the rear window.
This pattern of thin metal strips is specifically designed to distribute the heat evenly across the window, preventing it from being concentrated in one area and potentially causing damage to the glass. The defroster strips also help to improve aerodynamics by reducing drag and improving airflow over the rear of the car.
Overall, the purpose of the rear defroster is to improve visibility for the driver by quickly clearing the rear window of any fog, frost, or condensation, thereby enhancing safety while driving.