How to Measure Speed?
4 Answers
By measuring the rolling radius of the tire, the distance covered by the number of rolling revolutions of the tire circumference, and calculating the differential ratio and transmission ratio. By measuring and calculating the cumulative displacement of the trajectory within a unit time, it is comprehensively converted into speed and mileage, which is displayed on the screen.
As someone who has driven for many years, I think the simplest way to measure speed is to look at the speedometer on the dashboard. It connects to wheel sensors and calculates the speed in real time, which is mostly accurate. If you suspect it's inaccurate, you can choose a straight road section to check tire pressure or compare it with a mobile GPS app—apps like Amap can display speed in real time. The manual measurement method is also practical: for example, measure a 100-meter distance after parking, drive through at a constant speed and record the time, then divide the time by 60 to get the speed, but don’t get too distracted while driving. Safety is key—control your speed and avoid speeding, and pay extra attention to road signs in the city. Remember that speed perception can change on different road surfaces, such as during rain, so calibrate your equipment regularly to ensure reliability. This method is sufficient for daily use, hassle-free and efficient.
I'm a cautious driver and often teach my child about speed measurement: first, use the built-in speedometer in the car, which provides intuitive and reliable readings. If unsure, download a free app like Baidu Maps' navigation feature to double-check the speed while driving. The manual method is great for education: for example, measure a 100-meter stretch of road, have the child note the time by the roadside to calculate speed, but emphasize safety and not attempting this while driving. The key is to keep the speed within the limit—watch for signs on city roads and use cruise control on highways. Test multiple times to familiarize yourself with the vehicle's response, ensuring safe family trips. This helps prevent accidents, and once it becomes a habit, it's twice the result with half the effort.
I often drive new cars and measure speed directly using the dashboard speedometer along with a mobile app for verification. Apps like QQ or WeChat Maps display real-time speed on the screen while navigating, and they can also record historical data. I've tried the manual method by stopping the car: finding an open space, measuring a distance like 200 meters, driving at a constant speed, and timing it to calculate speed. Speed measurement has been simplified by tech tools, and apps can even alert you when speeding. Just avoid traditional methods that distract you while driving—these tools are both convenient and accurate.
