Question 1: Define 'stopping distance' in the context of vehicle safety.

Answer: The total distance a vehicle travels from the moment a driver perceives a hazard to when the vehicle comes to a complete stop.

Question 2: List the two main components that make up the total stopping distance.

Answer: Reaction distance and braking distance.

Question 3: Explain how driver reaction time influences the overall stopping distance.

Answer: Longer reaction times increase the reaction distance, thereby increasing the total stopping distance.

Question 4: A car travelling at 20 m/s has a reaction time of 1.5 seconds. Calculate its reaction distance.

Answer: Reaction distance = speed × reaction time = 20 m/s × 1.5 s = 30 metres.

Question 5: If the same car applies brakes and takes 4 seconds to stop from 20 m/s, calculate its braking distance. (Use the formula: v² = u² + 2as, where v=0, u=initial velocity, a=acceleration, s=distance).

Answer: v² = u² + 2as; 0 = (20)² + 2 × a × s; 0 = 400 + 2a s; a = - (v - u) / t = - (0 - 20) / 4 = -5 m/s²; s = (u²) / (2 × |a|) = 400 / (2 × 5) = 40 metres.

Question 6: Identify three factors that can increase braking distance in consumer vehicles.

Answer: Poor road conditions, worn brake pads, higher vehicle weight.

Question 7: A bicycle rider travelling at 5 m/s notices an obstacle and takes 0.75 seconds to react before applying brakes. Calculate the reaction distance.

Answer: Reaction distance = 5 m/s × 0.75 s = 3.75 metres.

Question 8: Describe a simple experiment that could be used to measure the braking distance of a small car toy. Include variables to control and safety precautions.

Answer: Set up a flat, smooth surface and mark a starting point. Release the toy car from a fixed height and measure the distance travelled after applying brakes at a set speed. Control variables include the initial speed, surface type, and brake force. Safety precautions involve ensuring the area is clear of obstacles and wearing protective gear if necessary.

Question 9: Data shows that a certain electric car has a reaction time of 1.2 seconds and a braking distance of 35 metres from 25 m/s. Analyse how reducing the reaction time to 0.8 seconds would impact the total stopping distance, assuming braking distance remains constant.

Answer: Reducing reaction time decreases reaction distance from 25 m/s × 1.2 s = 30 metres to 25 m/s × 0.8 s = 20 metres. Therefore, the total stopping distance reduces from 35 + 30 = 65 metres to 35 + 20 = 55 metres, enhancing safety by decreasing the overall stopping distance.

Question 10: Discuss how modern consumer vehicle technologies, such as anti-lock braking systems (ABS) and emergency brake assist, help reduce stopping distances and improve safety.

Answer: ABS prevents wheel lock-up during braking, maintaining steering control and reducing braking distance on slippery surfaces. Emergency brake assist detects rapid brake pedal application and increases braking force automatically, shortening stopping distances. Both technologies help drivers react more effectively and stop more quickly, thus reducing the risk of accidents.