Question 401476
how many years would it take to move {{{1}}} km  at {{{1}}} nm/sec?
{{{1}}} km = {{{10^3}}} m
{{{10^3}}} m = {{{10^12}}} nm
{{{t[1]}}} = ({{{10^12}}} nm)/({{{1}}} nm/sec)
This is time in seconds. To get time in years, convert {{{1}}} sec to years
{{{1}}} sec x {{{1/3600}}} hrs/sec x {{{1/24}}} days/hr x {{{1/365}}} yrs/day = {{{1/31536000}}} yrs
{{{1}}} sec = {{{3.170979*10^(-8)}}} yrs
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{{{t[1]*(1/40)}}} =  ({{{10^12}}} nm)/({{{40}}} nm/sec)
and
{{{t[1]*(.75/40)}}} =  ({{{.75*10^12}}} nm)/({{{40}}} nm/sec)
{{{.01875*t[1] = .01875*10^12}}}  sec
call the left side {{{t}}} in sec
{{{t = .01875*10^12}}} sec
{{{t = .01875*10^12 * 3.170979*10^(-8)}}} sec x yrs/sec
{{{t = .0594*10^4}}} yrs
{{{t = 594}}} yrs
It would take 594 years
Whew! Hope I got it.