Light waves travel with the speed of `3 xx 10^(8) "m s"^(-1)`. Express the speed in miles are per hour.

Answer

`6.75 xx 10^(8) "miles/hr"`

Explanation

`1.6 xx 10^(3)m=1" mile" :. "conversion factor"=(("1 mol"))/((1.6xx10^(3)m))`
`3.6 xx 10^(3)s=1hr:. "conversion factor"=((1hr))/((3.6xx10^(3)s))`
`(3xx10^(8)m)/(1s)=((3xx10^(8)m)xx("conversion factor"))/(1sxx("conversion factor"))`
`=(3xx10^(8)m)xx(("1 mile"))/((1.6xx10^(3)m))xx(1)/((1s))xx((3.6xx10^(3)s))/((1hr))=6.75xx10^(8) "miles/hr"`.