How wide is approximately 30cm in the rearview mirror?
2 Answers
At a distance of 30 centimeters from the rearview mirror, the field of view in the mirror is roughly the width of two fingers. Methods to determine the 30cm distance from the rearview mirror when taking a driving test include: Observing the wiper protrusion: From the driver's seat, when the protrusion of the wiper aligns with the right-side line, the distance is approximately 30 centimeters. Looking at the one-third point of the car's front: When the one-third point of the car's front aligns with the right-side line, the distance is exactly 30 centimeters. Explanation: Driving a motor vehicle requires certain driving skills. Without these skills, driving a vehicle recklessly may lead to traffic accidents. Generally, individuals without a license are not allowed to drive on the road. However, for those who have mastered safe driving techniques, the permit allowing them to drive on the road is the 'driver's license'.
Through years of driving, I've summarized the 30cm observation experience with rearview mirrors. The interior rearview mirror is typically flat, maintaining the actual size of objects, so a 30cm-wide object appears proportionally the same in the mirror. However, side mirrors (wing mirrors) are convex and shrink the image—a 30cm-wide object 30cm away might only appear 15-20cm wide in the mirror, depending on the mirror's design. In practical driving, I never rely solely on mirrors to judge such small distances, as errors can easily lead to scrapes or accidents. I recommend using rearview cameras or sensors when reversing to observe the actual distance, developing a habit of slow movement and thorough checks for safety. After all, mirrors are designed for broader visibility, not precise measurements.
