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)#
