# what is the speed of light (in kilometers an hour)?

• 299 792 458 m / s * 1 km/1000 m = 299792.458 km/s

299792.458 km /s * 3600 s/ 1 hr = 1079252848.8 km/hr

1.079 X 10^9 km/hr with sig figs.

• The speed of light varies based on what it is traveling through.

In a vacuum, light is the fastest and can travel over a billion kilometers (1,079,252,848) in an hour. But in other materials like glass, water or plasma, light travels more slowly, sometimes much more slowly.

For example, the sun s radius is roughly 700 thousand kilometers, yet it takes light thousands of years to get from the center to the surface.

However, once in the vacuum of space, it travels the distance to Earth (about 150 million kilometers) in just about 8 minutes.

Pretty fricken cool.

• Speed Of Light In Km

• To be accurate the speed of light = 1.07925285 × 10^9 kilometers / hr.

• Light travels at a speed of 186,000 miles (299,338 Km) a second or 700 million miles (1,126,540,800 Km) an hour.

The distance from the Earth to the Moon is about 239,000 miles (384,633 kM). This seems pretty fast and indeed theory says that nothing can travel faster than the speed of light

RE:

what is the speed of light (in kilometers an hour)?

• Speed of light is 300000 kilometers per second. You can multiply that out by the number of seconds in an hour.

• Its a very easy question.Any school student knows that speed of light is 3*10^5km/s,that is,300,000 km/s.Multiplying by 3600,as there are 3600 sec in an hour,we get 300000*3600=1,080,000,000 kmph or 1 billion 80 million kilometers an hour.Simple!!

However the speed of light is dependent on the medium its travellling in.The above speed is for vacuum or in air with approximation.As the medium gets denser, the speed reduces as per a quantity defined as the refractive index of the medium.Speed in a medium with refractive index of x will have a speed of S/x,where S=speed of light in vacuum or air.

• 3 times 10 to 8 Metres per second,

So 3 times 10 to 5 KM per second

• 180,000 mileas per second. Given the E=MC2, Time Travel is relativey possible at speeds well in excess of the same.Use respective formula to covert from miles to kilometers.