Homework: Math question?

Question

An object is traveling at a speed of 30 feet per second. What is the speed in miles per hour?


If you could, explain how you got the answer.

Answer 1

1. Convert feet to miles.



1 mile = 5280 ft so 1/5280 = x/30



x = 30/5280



2. Convert seconds to hours



1 hour = 3600 seconds so 1 second = 1/3600 hour



3. Now divide miles by hours



30/5280 div. by 1/3600



30/5280 x 3600/1 = 108,000 / 5280 = 20.45 mi/h

Answer 2

Just set up the calculation so that the units cancel out correctly for you to end up with miles/hour:



(30 feet / 1 second) * (1 mile / 5280 feet) * (60 seconds / 1 minute) * (60 minutes / 1 hour) =



(30 * 60 * 60 / 5280) miles/hour = 20 5/11 miles/hour = 20.454545... miles/hour

Answer 3

see!

1foot = 12 inches

and, 1 inch = 2.54 cm!

So, 12 inch = 12*2.54 = 30.48cm

So, 1 foot = 30.48cm

so, 30 feet = 30*30.48 cm = 914.4 cm

Now, 1 mile = 1609.344m

So, 1 mile = 160934.4 cm

So, 1 cm = 1/160934.4

So, 914.4 cm = 914.4/160934.4 = 0.005608



Now, 1 sec = 1/3600 hrs

So, speed in miles per hour is

[5608/1000000]/[1/3600] = (5608*36)/10000

= 201888/10000 = 20.188 miles per hour



Hope this helps, though the calculations are quite tough!

Answer 4

1mile=5280 feet so 1 feet = 1/5280 s0 30ft=30/5280

1hour=3600 second so 1 sec=1/3600 hr



so 30ft/s= 30/5280/1/3600 mile/hr= 30/(5280x 3600) mile/hr = 20.45 mile/hr

Answer 5

1mile=5280 feet.

1 hour =3600 seconds.

30/5280*3600=20.45 MPH