Question 1: Define the law of reflection in your own words.

Answer: The law of reflection states that the angle of incidence equals the angle of reflection, and both angles are measured relative to the normal to the surface.

Question 2: Explain why rearview mirrors in vehicles are designed with a reflective surface.

Answer: Rearview mirrors are designed with reflective surfaces to redirect light from behind the vehicle to the driver’s eyes, enabling visibility of the rear traffic.

Question 3: What type of mirror is typically used in car side mirrors and why?

Answer: Convex mirrors are used because they provide a wider field of view, allowing the driver to see more area behind and to the sides of the vehicle.

Question 1: A car's side mirror is convex with a radius of curvature of 1.2 meters. Calculate the focal length of the mirror. (Use the mirror formula: f = R/2).

Answer: Focal length, f = R/2 = 1.2 m / 2 = 0.6 meters.

Question 2: If a light ray strikes the reflective surface of a car mirror at an incident angle of 30 degrees relative to the normal, what is the angle of reflection?

Answer: The angle of reflection is equal to the angle of incidence, so 30 degrees.

Question 3: A vehicle's rearview mirror reflects light from an object behind the car located 50 meters away. If the mirror is inclined at 45 degrees, what is the minimum distance from the mirror to the object for the light to reflect directly into the driver’s eyes at a 60-degree incident angle? (Assume ideal reflection).

Answer: This involves applying the law of reflection and basic trigonometry; the detailed calculation shows the object must be approximately 50 meters behind, considering the angles involved.

Question 1: Describe the safety advantages of using convex mirrors on vehicles.

Answer: Convex mirrors provide a wider field of view, reducing blind spots and helping drivers detect vehicles or obstacles earlier, thus enhancing safety.

Question 2: List two safety precautions drivers should take when relying on reflective surfaces for visibility.

Answer: Drivers should regularly clean mirrors to maintain clarity and avoid relying solely on mirrors in poor weather conditions like heavy rain or fog.

Question 3: Propose a simple experiment to demonstrate how the angle of incidence equals the angle of reflection using a reflective surface and a light source.

Answer: Set up a flat reflective surface, such as a mirror, and shine a laser or light beam at a known incident angle. Mark the incident and reflected rays, then measure the angles relative to the normal. Repeat with different angles to confirm the law of reflection.

Question 1: A car manufacturer claims that their new convex side mirrors can reduce blind spots by 25%. Explain how the law of reflection and the shape of the mirror contribute to this improvement.

Answer: Convex mirrors reflect light over a wider area due to their curved surface, increasing the field of view. According to the law of reflection, the light from a broader area is directed towards the driver’s eyes, reducing blind spots.

Question 2: In a safety test, a reflective strip is placed on the back of a bicycle. When headlights shine on it from 10 meters away, the light reflects back towards the driver. How does reflection enhance the visibility of the bicycle at night?

Answer: Reflection directs the light back towards the source (driver’s eyes), making the bicycle visible at night, which helps prevent accidents.

Question 3: Explain why reflective safety surfaces on roads are often made with materials like aluminium or sulphur compounds, considering the physics of reflection.

Answer: Materials like aluminium and sulphur compounds are highly reflective and durable, allowing them to efficiently reflect light from vehicle headlights back to drivers, especially in low-light conditions, enhancing road safety.