Question 1: Define the term 'ventilation' in the context of the respiratory system.

Answer: Ventilation is the process of moving air in and out of the lungs to facilitate gas exchange.

Question 2: Describe how the diaphragm contributes to breathing during inhalation.

Answer: The diaphragm contracts and moves downward, increasing the thoracic cavity volume and reducing pressure, causing air to flow into the lungs.

Question 3: In automotive ventilation systems, which principle of the respiratory system is applied to regulate airflow?

Answer: Negative pressure ventilation

Question 4: Fill in the blank: The volume of air inhaled or exhaled in a normal breath is called __________.

Answer: tidal volume

Question 5: Explain why a car's ventilation system needs to mimic the negative pressure mechanism of human breathing.

Answer: A car's ventilation system needs to create a negative pressure environment to draw fresh air into the cabin efficiently, similar to how the diaphragm lowers the thoracic cavity during inhalation. This ensures proper airflow, maintains air quality, and provides comfort for passengers, especially in sealed environments.

Question 1: Calculate the amount of air (in litres) inhaled in one minute if a person takes 12 breaths per minute with a tidal volume of 0.5 litres. Use the formula: Total Air Volume = Breaths per minute × Tidal volume.

Answer: 6 litres

Question 1: Design a simple experiment to compare the efficiency of different automotive ventilation systems in maintaining air quality. Identify the variables involved and safety precautions.

Answer: Students could set up models of ventilation systems with fans and filters, measuring air quality using particulate sensors under different conditions. Variables include airflow rate, filter type, and external pollution levels. Safety precautions involve ensuring electrical safety, avoiding inhalation of dust or pollutants, and proper handling of electrical equipment.

Question 1: A study shows that a sealed vehicle cabin maintains a negative pressure of 5 Pa relative to the outside environment during operation. Explain how this negative pressure influences airflow and passenger comfort.

Answer: The negative pressure draws fresh air into the cabin from outside, preventing the ingress of pollutants. It helps maintain a steady airflow, improves air quality, and ensures passenger comfort by reducing stale or contaminated air inside the vehicle.

Question 1: Discuss the similarities and differences between the human breathing mechanism and the ventilation system used in modern cars. Include explanations of pressure changes, airflow, and safety considerations. (6 marks)

Answer: Both human breathing and automotive ventilation systems rely on creating pressure differences to move air. Humans use the diaphragm to generate negative pressure, drawing air into the lungs. In contrast, cars use fans and negative pressure chambers to draw air into the cabin. Key differences include biological control and adaptation in humans versus mechanical control in vehicles. Similarities involve maintaining airflow and air quality, but safety considerations differ; humans need to avoid inhaling harmful substances, while vehicles must prevent the ingress of pollutants and ensure proper filtration.