okay, the speed of light is 3x10^8 meters/sec. and something is 20 lightyears away...?

1 ⤊

how far is 20 lightyears in both miles and meters, when the speed of light in a vacuum is 3x10^8 meters/second???

this is for school

2007-04-26 02:17:08 · 2 answers · asked by white_penguin2004 2 in Science & Mathematics ➔ Astronomy & Space

In round numbers, 20 light years is 120 trillion miles. That would be about 200 trillion kilometers or 200 quadrillion meters. In round numbers.

2007-04-26 02:41:05 · answer #1 · answered by campbelp2002 7 · 1⤊ 0⤋

A light year is a measure of distance.

x = v*t = 3x10^8*(60*60*24*365.25) = 9.5x10^15 m

1 km equal 0.62 miles

hence it equals 5.9x10^12 miles

2007-04-26 02:24:04 · answer #2 · answered by dudara 4 · 0⤊ 1⤋