Question 1: Seismic waves are elastic waves that travel through the Earth, often generated by earthquakes or explosions. In the automotive industry, seismic sensors detect vibrations caused by road impacts or structural faults to ensure vehicle safety and integrity.

Answer: Seismic waves are elastic waves travelling through the Earth, used in automotive sensors to detect vibrations for safety.

Question 1: Define seismic waves and name the two main types.

Answer: Seismic waves are elastic waves that travel through the Earth; the two main types are P-waves (primary) and S-waves (secondary).

Question 2: Explain how seismic waves are generated and how they can be detected in vehicles.

Answer: Seismic waves are generated by sudden movements like earthquakes or explosions. In vehicles, accelerometers or seismic sensors detect vibrations caused by impacts or structural issues, converting mechanical vibrations into electrical signals.

Question 1: A seismic wave travels through the Earth's crust at a speed of 6 km/s. If the wave originated 150 km away from a vehicle, how long does it take for the wave to reach the vehicle? Show your working.

Answer: Time = Distance / Speed = 150 km / 6 km/s = 25 seconds.

Question 2: Calculate the frequency of seismic waves with a wavelength of 10 km travelling at 6 km/s. Use the formula v = f × λ. Provide your answer in Hz.

Answer: f = v / λ = 6 km/s / 10 km = 0.6 Hz.

Question 1: Describe a basic experimental setup that could be used to measure vibrations in a vehicle caused by seismic waves. Include the instruments involved and safety considerations.

Answer: A possible setup includes placing accelerometers or seismic sensors attached to the vehicle's chassis to record vibrations. The sensors connect to a data logger or computer for analysis. Safety considerations involve ensuring sensors are securely attached, avoiding electrical hazards, and conducting tests in controlled environments to prevent injury.

Question 1: A vehicle detects increased seismic activity when passing over a certain segment of road. The seismic sensors record vibrations with amplitudes ranging from 0.5 mm to 2 mm. What might this indicate about the road's condition?

Answer: The increased vibrations suggest possible structural faults, potholes, or underlying instability in that road segment.

Question 1: Explain how seismic waves can be utilised in automotive safety systems to prevent accidents. Include in your answer the types of seismic waves involved and their detection methods. (6 marks)

Answer: Seismic waves are used in automotive safety systems through sensors that detect vibrations caused by impacts or structural faults. P-waves, which are faster and compressional, and S-waves, which are shear and slower, can be detected using accelerometers and piezoelectric sensors. These sensors convert mechanical vibrations into electrical signals that trigger safety responses like airbag deployment or structural adjustments, helping to prevent accidents and improve vehicle integrity.

Question 1: In the automotive industry, seismic sensors are used to monitor structural health. How might understanding seismic wave properties improve the design of vehicle safety systems?

Answer: Understanding seismic wave properties helps in designing sensors that accurately detect relevant vibrations, enabling early detection of faults and enhancing safety features like impact mitigation and structural integrity.