Question

Lane knows that when he runs, he takes about 180 steps per minute and that each step is 3.25 feet long. Which calculation is most reasonable for Lane to use to find out his running speed in miles per hour?

Answer 1

180 x 3.25 x 60/5280
6.64 mph (rounded)

Answer 2

lane´s speed is 6.64 mi/h

Explanation:

Hello

this is a usual problem of unit conversion

step 1

convert steps⇒ft

let

3.25 ft = 1 step

Velocity=180 steps / min

we can eliminate the units multiplying by

`(3.25 ft)/( 1\ step)`

because that=1

to change the units

the fraction must be accommodated to change the unit

`\\180(step)/(min) *(3.25 ft)/( 1\ step) =180*3.25(ft)/(min)\\`

Step 2

converts ft ⇒mile

1m=5280 ft

`=180*3.25(ft)/(min)=585 (ft)/(min) \\\\and\ again\ we\ use\ the\ conversion\to\change\unit\\\\\\\\585 (ft)/(min) *((1 mi)/(5280\ ft))= ((585)/(5280))\ (mi)/(min)`

the fraction must be accommodated to change the unit

step 3

converts minutes ⇒hours

60 minutes = 1 hour

`((585)/(5280))\ (mi)/(min)*(60\ min)/(1\ hour) =(60*585\ min)/(5280 hour)\\ =6.64 (mi)/(hour) \\V=6.64 (mi)/(hour)`

V=6.64 mi/h

now we Know lane´s speed is 6.64 mi/h