# محول السرعة

> حوّل ⁨mph⁩ إلى ⁨km/h⁩ و⁨km/h⁩ إلى ⁨mph⁩ و⁨m/s⁩ والعقد بعوامل دقيقة، مع ⁨ft/s⁩ وماخ عند مستوى البحر وسرعة الضوء.

النسخة التفاعلية: https://www.calcopenly.com/ar/conversion/speed-converter
الموضوع: محولات الوحدات

Each speed unit is a fixed number of metres per second. The road and sea units are exact: a mile per hour is 0.44704 m/s because the mile is 1,609.344 m, a kilometre per hour is 1/3.6 m/s, and a knot, one nautical mile per hour, is 1,852/3,600 m/s.

The default converts 60 mph to 96.56064 km/h, the figure a UK or US driver needs on metric roads. Sailors and pilots work in knots, and 1 knot is exactly 1.852 km/h.

Mach is fixed here at 340.294 m/s, the speed of sound in the International Standard Atmosphere at sea level and 15 °C, and results that use it are marked approximate because the real speed of sound falls with temperature. The speed of light is exactly 299,792,458 m/s by definition.

## المدخلات

- **القيمة**: عدد بوحدة المصدر، أو عدد مرفق بوحدته الخاصة
- **من** (الخيارات: metre per second (m/s), kilometre per hour (km/h), mile per hour (mph), knot (kn), foot per second (ft/s), kilometre per second (km/s), Mach (sea level) (Ma), speed of light (c))
- **إلى** (الخيارات: metre per second (m/s), kilometre per hour (km/h), mile per hour (mph), knot (kn), foot per second (ft/s), kilometre per second (km/s), Mach (sea level) (Ma), speed of light (c))

## النتائج

- القيمة بعد التحويل — النتيجة الرئيسية
- التحويل
- عامل التحويل
- الدقة

## الصيغة

$$
\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{m/s} \end{gathered}
$$

## أمثلة محلولة

### 60 mph in km/h

- القيمة: 60 mph
- من: mile per hour (mph)
- إلى: kilometre per hour (km/h)
- **القيمة بعد التحويل: 96.56064 km/h**
- **الدقة: دقيق**
- مصدر التحقق: ⁨60 × 1609.344 m / 1000 = 96.56064 km/h (1 mi = 1609.344 m, NIST HB 44)⁩

### 1 knot in km/h

- القيمة: 1 kn
- من: knot (kn)
- إلى: kilometre per hour (km/h)
- **القيمة بعد التحويل: 1.852 km/h**
- مصدر التحقق: ⁨1 knot = 1 nautical mile per hour = 1852 m/h (NIST SP 811 App. B)⁩

### 100 km/h in m/s

- القيمة: 100 km/h
- من: kilometre per hour (km/h)
- إلى: metre per second (m/s)
- **القيمة بعد التحويل: 27.7777777778 m/s**
- **الدقة: تعريفات دقيقة، عدد عشري دوري**
- مصدر التحقق: ⁨100000 m / 3600 s = 250/9 (Python 3.8 fractions from the legal definitions)⁩

### Speed of light in km/s

- القيمة: 1 c
- من: speed of light (c)
- إلى: kilometre per second (km/s)
- **القيمة بعد التحويل: 299,792.458 km/s**
- مصدر التحقق: ⁨c = 299,792,458 m/s exactly (SI definition of the metre)⁩

### Mach 1 at sea level (approximate)

- القيمة: 1 Ma
- من: Mach (sea level) (Ma)
- إلى: kilometre per hour (km/h)
- **القيمة بعد التحويل: 1,225.0584 km/h**
- **الدقة: تقريبي**
- مصدر التحقق: ⁨340.294 m/s (ISA sea level, 15 °C) × 3.6 = 1225.0584 km/h⁩

## الأسئلة

### How do I convert mph to km/h?

Multiply by 1.609344: 60 mph × 1.609344 = 96.56064 km/h, and 70 mph is 112.65 km/h. The factor is exact because a mile is exactly 1,609.344 m. Multiplying by 1.6 is a mental shortcut that comes out 0.6% low; to go from km/h to mph, multiply by 0.621371.

### How do I convert km/h to m/s?

Divide by 3.6, because an hour has 3,600 seconds and a kilometre 1,000 metres. 100 km/h is 27.78 m/s and 36 km/h is exactly 10 m/s. Multiply by 3.6 to go back: a sprinter at 10 m/s is running 36 km/h, or 22.37 mph.

### What is a knot in mph and km/h?

One knot is exactly 1.852 km/h, about 1.15078 mph or 0.514444 m/s. It is one nautical mile (1,852 m) per hour, the speed unit of shipping and aviation, so a 30-knot wind is 55.56 km/h or 34.52 mph.

### How fast is Mach 1?

In the International Standard Atmosphere at sea level (15 °C) it is 340.294 m/s, which is 1,225.06 km/h or 761.22 mph, the value this converter uses. The speed of sound depends on air temperature, so at 11 km altitude, where the standard atmosphere is −56.5 °C, Mach 1 is about 295 m/s or 1,062 km/h.

### Why is the speed of light an exact number?

Because the metre is defined from it. Since 1983 the metre has been the distance light travels in vacuum in 1/299,792,458 of a second, which fixes c at exactly 299,792,458 m/s, or 1,079,252,848.8 km/h. Converting c into any unit here is therefore exact.

### ما مدى دقة «⁨محول السرعة⁩»؟

تعتمد الدقة على مدخلاتك وافتراضات الطريقة. يستخدم الحساب العشري 50 رقمًا معنويًا، لكن التقديرات والأساليب العددية وبيانات المصدر قد تكون أقل دقة؛ تقريب القيم المعروضة لا يزيل هذه الحدود. أمثلة محلولة جرى التحقق منها بمصادر مستقلة: 5. مثلًا، يجري التحقق من «⁨60 mph in km/h⁩» بالرجوع إلى ⁨60 × 1609.344 m / 1000 = 96.56064 km/h (1 mi = 1609.344 m, NIST HB 44)⁩.

### ما مصدر هذه الطريقة؟

NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors; NIST Handbook 44, Appendix C — General tables of units of measurement.

## المصادر

- [NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors](https://www.nist.gov/pml/special-publication-811)
- [NIST Handbook 44, Appendix C — General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)