Kilometers Per Second to Light Speed
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How to convert

1 kilometer per second (km/s) = 3.33564E-06 light speed (ls). Kilometer Per Second (km/s) is a unit of Speed used in Metric system. Light Speed (ls) is a unit of Speed used in Metric system.

Kilometers per second: A unit of speed

Kilometers per second (km/s) is a unit of speed or velocity in the International System of Units (SI). It measures how fast an object is moving by calculating the distance traveled in kilometers divided by the time taken in seconds. For example, if a rocket travels 10 kilometers in 5 seconds, its speed is 2 km/s.

How to convert kilometers per second

Kilometers per second can be converted to other units of speed or velocity by using simple conversion factors. Here are some common units and their conversion factors:

• Meters per second (m/s): To convert from km/s to m/s, multiply by 1000. To convert from m/s to km/s, divide by 1000. For example, 2 km/s is equal to 2000 m/s, and 500 m/s is equal to 0.5 km/s.
• Kilometers per hour (km/h): To convert from km/s to km/h, multiply by 3600. To convert from km/h to km/s, divide by 3600. For example, 2 km/s is equal to 7200 km/h, and 100 km/h is equal to 0.028 km/s.
• Miles per hour (mph): To convert from km/s to mph, multiply by 2236.94. To convert from mph to km/s, divide by 2236.94. For example, 2 km/s is equal to 4473.88 mph, and 60 mph is equal to 0.027 km/s.
• Knots (kn): To convert from km/s to kn, multiply by 1943.84. To convert from kn to km/s, divide by 1943.84. For example, 2 km/s is equal to 3887.68 kn, and 30 kn is equal to 0.015 km/s.
• Feet per second (ft/s): To convert from km/s to ft/s, multiply by 3280.84. To convert from ft/s to km/s, divide by 3280.84. For example, 2 km/s is equal to 6561.68 ft/s, and 100 ft/s is equal to 0.03 km/s.
• Miles per second (mi/s): To convert from km/s to mi/s, multiply by 0.621371. To convert from mi/s to km/s, divide by 0.621371. For example, 2 km/s is equal to 1.24 mi/s, and 1 mi/s is equal to 1.61 km/s.

Where kilometers per second are used

Kilometers per second are mainly used in astronomy and space science to measure the speed or velocity of celestial bodies and spacecrafts.

For example, the Earth orbits the Sun at an average speed of about 30 km/s.

The Moon orbits the Earth at an average speed of about 1 km/s.

The International Space Station orbits the Earth at an average speed of about 7.66 km/s.

The Voyager 1 spacecraft, which is the farthest human-made object from Earth, travels at a speed of about 17 km/s.

The speed of light in a vacuum is about 300000 km/s.

Definition of kilometers per second

According to the SI definition, one kilometer per second is the speed of a body that covers a distance of one kilometer in a time of one second.

Mathematically, it can be expressed as:

v = s / t

where v is the speed or velocity in kilometers per second, s is the distance traveled in kilometers, and t is the time taken in seconds.

History of kilometers per second

The concept of speed or velocity has been studied since ancient times by philosophers and scientists such as Aristotle, Galileo, Newton, etc.

The kilometer was originally defined in 1793 by the French Academy of Sciences as one ten-millionth of the distance from the equator to the North Pole along a meridian through Paris.

The second was originally defined in terms of the Earth’s rotation as one eighty-six thousand four hundredth of a mean solar day.

The combination of these two units resulted in the kilometer per second as a unit of speed or velocity.

The kilometer per second was officially adopted as part of the SI system in 1960.

Example conversions of kilometers per second to other units

Here are some examples of converting kilometers per second to other units of speed or velocity:

• 1 km/s =1000 m/s = 3600 km/h = 2236.94 mph = 1943.84 kn = 3280.84 ft/s = 0.62 mi/s
• 2 km/s = 2000 m/s = 7200 km/h = 4473.88 mph = 3887.68 kn = 6561.68 ft/s = 1.24 mi/s
• 5 km/s = 5000 m/s = 18000 km/h = 11184.7 mph = 9721.92 kn = 16404.2 ft/s = 3.11 mi/s
• 10 km/s = 10000 m/s = 36000 km/h = 22369.4 mph = 19438.4 kn = 32808.4 ft/s = 6.21 mi/s
• 20 km/s = 20000 m/s = 72000 km/h = 44738.8 mph = 38876.8 kn = 65616.8 ft/s = 12.43 mi/s
• 50 km/s = 50000 m/s = 180000 km/h = 111847 mph = 97219.2 kn = 164042 ft/s = 31.07 mi/s
• 100 km/s = 100000 m/s = 360000 km/h = 223694 mph = 194384 kn = 328084 ft/s = 62.14 mi/s

Light Speed

Definition of Light Speed

Light speed, commonly denoted c, is a universal physical constant that is exactly equal to 299,792,458 metres per second (approximately 300,000 kilometres per second; 186,000 miles per second; 671 million miles per hour). It is the speed at which light waves propagate through vacuum, and also the upper limit for the speed at which any form of matter or energy can travel through space. Light speed is an essential parameter in the theories of relativity and electromagnetism, and has relevance beyond the context of light and electromagnetic waves.

How to Convert Light Speed

To convert light speed to other units of speed, we need to multiply or divide by the corresponding conversion factors. For example, to convert light speed to kilometers per hour, we need to multiply by 3,600, since there are 3,600 seconds in one hour. To convert light speed to miles per hour, we need to multiply by 2.2369362920544, since there are 2.2369362920544 miles in one kilometer.

Here are some examples of how to convert light speed to other units of length in the US Standard system and the SI system:

• To convert c to kilometers per hour (km/h), we multiply by 3,600: c x 3,600 = 1,079,252,848.8 km/h
• To convert c to miles per hour (mph), we multiply by 2.2369362920544: c x 2.2369362920544 = 670,616,629.384 mph
• To convert c to feet per second (fps), we multiply by 3.2808398950131, since there are 3.2808398950131 feet in one meter: c x 3.2808398950131 = 983,571,056.43 fps
• To convert c to knots (kn), we multiply by 1.9438444924406, since there are 1.9438444924406 nautical miles in one kilometer: c x 1.9438444924406 = 582,749,918.284 kn
• To convert c to meters per second (m/s), we use the exact value: c = 299,792,458 m/s
• To convert c to meters per minute (m/min), we multiply by 60, since there are 60 seconds in one minute: c x 60 = 17,987,547,480 m/min

Where Light Speed Is Used

Light speed is used in various fields of science and technology where the properties and behavior of light and electromagnetic waves are studied or applied. For example:

• In astronomy and cosmology, light speed is used to measure astronomical distances and time scales, such as light-years and parsecs. It also determines the observable size and age of the universe and the effects of gravity on light such as gravitational lensing and gravitational redshift.
• In physics and engineering, light speed is used to calculate the energy and momentum of particles and fields using the famous equation E = mc2. It also sets the limit for causality and information transfer in physical systems.
• In communication and navigation, light speed is used to determine the delay and bandwidth of signals transmitted through various media such as optical fibers or radio waves. It also affects the accuracy and precision of measurements based on time-of-flight or Doppler effect methods.

History of Light Speed

The concept of light speed has a long history that spans across different cultures and disciplines. Some of the milestones in its development are:

• In ancient times, many philosophers and scientists assumed that light traveled instantaneously or infinitely fast.
• In the late 17th century, Danish astronomer Ole Romer was the first to demonstrate that light had a finite speed by observing the apparent motion of Jupiter’s moon Io. He estimated that light took about 22 minutes to cross the diameter of Earth’s orbit.
• In the early 18th century, English astronomer James Bradley discovered the aberration of starlight caused by Earth’s motion around the Sun. He used this phenomenon to calculate that light traveled about 10 thousand times faster than Earth’s orbital speed.
• In the late 19th century, French physicist Hippolyte Fizeau and American physicist Albert Michelson conducted various experiments using rotating mirrors or interferometers to measure the speed of light more accurately in air or vacuum.
• In the early 20th century, German-born physicist Albert Einstein proposed the special theory of relativity, which postulated that light speed was constant and independent of the motion of the source or the observer. He also showed that light speed was the maximum speed for any form of matter or energy in the universe.
• In the late 20th century, various methods and standards were developed to define and measure light speed more precisely and consistently. In 1983, the International System of Units (SI) adopted the exact value of 299,792,458 metres per second as the definition of light speed in vacuum.

Example Conversions of Light Speed to Other Units

Here are some examples of how to convert light speed to other units of speed, using the conversion factors given above:

• To convert c to kilometers per hour, we multiply by 3,600: c x 3,600 = 1,079,252,848.8 km/h
• To convert c to miles per hour, we multiply by 2.2369362920544: c x 2.2369362920544 = 670,616,629.384 mph
• To convert c to feet per second, we multiply by 3.2808398950131: c x 3.2808398950131 = 983,571,056.43 fps
• To convert c to knots, we multiply by 1.9438444924406: c x 1.9438444924406 = 582,749,918.284 kn
• To convert c to meters per second, we use the exact value: c = 299,792,458 m/s
• To convert c to meters per minute, we multiply by 60: c x 60 = 17,987,547,480 m/min
• To convert c to centimeters per second, we multiply by 100: c x 100 = 29,979,245,800 cm/s