# kilometers per hour (km / h) and meters per second (m / s) Conversion Calculator

An online kilometers per hour (km/h) and meters per second (m/s) conversion calculator is presented. Examples and problems involving convertion of km/h and m/s are also included.

## Conversion Formula of Kilometers per Hour (km / h) and Meters per Second (m / s) [1]

Given that

1 km = 1000 m

1 hour = 3600 seconds

We have

1 km / h = ( 1 × 1000 m ) / ( 3600 s ) = (5/18) m/s

and

1 m / s = (18 / 5) km / h = 3.6 km / h

## Examples of Conversion

Example 1 - The speed S of a car in 100 km / h. What is the speed of this car in m / s? Round the answer to the nearest unit.

S = 100 km / h = 100 × (5/18) m / s = 27.7777777778 m/s

Round to the nearest unit

S = 28 m / s

Example 2 - A car is traveling at 27 m / s and a second car traveling at 90 km / h. Which car is traveling faster?

Convert 27 m / s to km / h

27 m / s = 27 × 3.6 km / h = 87.2 km / h

The car traveling at 27 m / s is faster.

## Use of Conversion Calculator

Enter the number of km / h or m / s and convert.

## Problems Involving km/h and m/s Conversions

Problem 1

The speed of light is equal to 299792458 m / s. What is the speed of light in km / h?

Solution

299792458 m / s = 299792458 × 3.6 km / h = 1079252848.8 km / h

Problem 2

What is the ratio R of the speed of light which equal to 299792458 m / s and the speed of sound which is 1234.8 km / h? How much faster is the speed of light compared to the speed of sound?

Solution

We first need to convert the speed of sound in m / s

1234.8 km / h = 1234.8 m/s × (5/18) = 343 m / s

The ratio R is given by

R = ( 299792458 m / s ) / ( 343 m / s ) = 874030.489796

Round to the nearest unit

R = 874030

The speed of light is 874030 times faster than the speed of sound.

Problem 3

The speed of Mach 1 corresponds to the speed of sound.

A high speed jet figther has a speed of Mach 2.1. What is the speed of the jet fighter in km / h given that the speed of sound is equal to 343 m / s? Round the answer to the nearest unit.

Solution

The speed S of the jet fighter in m /s is given by

S = 2.1 × 343 m / s = 720.3 m / s

Convert S in km / h.

S = 720.3 m / s = 720.3 × 3.6 km / h = 2593.08 km / h.

Round to the nearest unit

S = 2593 km / h

### More References and links

- www.nist.gove.pdf
- Online Calculators
- Units Conversion and Calculators
- Geometry Calculators