每小时公里到每小时转换器

每小时几公里?

时速(km/h或kph)和时速(mph)是全世界最广泛使用的测量速度的两个单位. 它们虽然服务于同样的目的,但属于不同的测量系统,在不同的区域使用.

时速计的历史

The kilometer has its roots in France, where the French Academy of Sciences developed a new measurement system in 1793. Initially, the French used "millaire" (equal to 10,000 meters) before the term "kilometer" (1,000 meters) became standardized.

The term "kilometers per hour" began to appear in English literature in the 1860s. It wasn't until 1975 that a European Union directive required the use of the "km/h" abbreviation on all speedometers in cars sold within the EU.

每小时英里的历史

The mile has a much longer history, dating back to the Romans. The Roman mile ("mille passus") from 29 BC was defined as the length of 1,000 paces, where a pace was the distance of the left foot hitting the ground twice.

中世纪时期的"旧英语里程"大约为2.1公里. 现代国际里程(准确为1,609.344米)是1959年由美国,英国,加拿大,澳大利亚,新西兰和南非达成协议而确定的.

"Miles per hour" first became common with the advent of regular stage coaches. During the early 19th century, as railroads began operating at higher speeds, there were concerns that passengers might suffer harm at speeds exceeding 20 mph!

全球使用

今天,km/h被用作世界上大多数采用公制的国家的标准速度测量. 这包括整个欧洲大陆、亚洲、非洲、澳大利亚和拉丁美洲的大部分地区。

时速里程仍然是美国和联合王国的标准,尽管英国在其他地区已经基本改用度量衡系统.

科学定义和SI单位

在"国际单位制"(SI)中,速度的标准单位为米每秒(m/s). 每小时一公里等于0.27778米/秒,而每小时一英里等于0.44704米/秒.

The official SI symbol for kilometers per hour is "km/h", though non-SI abbreviations such as "kph", "kmph", and "km/hr" are also commonly used in various contexts.

转换关系

公里/小时与英里/小时之间的精确换算由千米与英里之间的关系来定义:

• 1英里=1.609344公里(准确)
• 因此,1 mph = 1.609344 km/h
• 反之,1公里/小时=0.621371 小时

通用引用速度