46 feet per second is written as (46ft)/(se c)
To convert seconds to hours we can multiply by the follow terms, each of which are equal to 1 so we are not changing the value of the term.
(46ft)/(se c) xx (60 se c)/(1 min) xx (60 min)/(1 hr) =>
(46ft)/(color(red)(cancel(color(black)(se c)))) xx (60 color(red)(cancel(color(black)(se c))))/(1 color(blue)(cancel(color(black)(min)))) xx (60 color(blue)(cancel(color(black)(min))))/(1 hr) =>
(46 xx 60 xx 60 ft)/(hr) =>
(165600 ft)/(hr)
We can now convert feet to miles by again multiplying by the following term which is equal to 1 so we are not changing the value of the term:
(165600 ft)/(hr) xx (1 mi)/(5280 ft) =>
(165600 color(red)(cancel(color(black)(ft))))/(hr) xx (1 mi)/(5280 color(red)(cancel(color(black)(ft)))) =>
(165600 xx 1 mi)/(5280 hr) =>
(165600 mi)/(5280 hr) =>
(31.bar36 mi)/(hr)
