Question

What is your average speed in miles per hour and in feet per second if you travel a mile in 21 ​minutes?

Answer 1

Answer: 2.857 miles/hr

4.19 ft/sec

Explanation:

60 min=1 hr.

1 mi/21 min*60 min=

60 min*1 mi/21 min=2.857 miles/hr

60 sec=1 min

60*60 sec=1 hr

1 hr=3600 sec

2.857 miles/hr=

2.857/3600 miles/sec=0.00079 miles/sec

1 mile=5280 ft

0.00079 miles/sec=

0.00079*5280 ft/sec=4.19 ft/sec

Answer 2

Answers:

2.857142 mph

4.190476 ft per second

Both values are approximate

=======================================================

Work Shown:

21 min = 21/60 = 0.35 hrs which is exact

distance = rate*time

rate = distance/time

rate = (1 mile)/(0.35 hrs)

rate = (1/0.35) mph

rate = 2.857142 mph which is approximate

------------------

21 min = 21*60 = 1260 seconds

1 mile = 5280 ft

rate = distance/time

rate = (5280 ft)/(1260 seconds)

rate = (5280/1260) ft per second

rate = 4.190476 ft per second approximately