Which is faster and why 90.0 miles per hour or 121 feet per second

90 miles per hr:

1 mile = 5280 ft ... so 90 miles = 90 (5280) = 475200 ft

1 hr = 3600 seconds

475200/3600 = 132 ft per second < = = this is equal to 90 miles per hr

the 90 miles per hr is faster then 121 ft per sec.