Question

(29) A runner is running 10 miles per hour.

Answer 1

The conversions factors needed are 1 mile= 5280 feet and 1 hour = 3600 seconds, speed in ft/s = 14.67 ft/s  

Solution:

Given, A runner is running 10 miles per hour.  

We have to find what conversion factors should be used to convert 10 mi/hr to ft/s?

Now, speed of runner = 10 miles per hour.

But we need the units to be in ft / s.

Then, conversion factors are miles to feet and hours to seconds.

Now, miles to feet ⇒ 1 mile = 5280 feet.

Now, hours to seconds ⇒ 1 hour = 3600 seconds

$\begin{array}{l}{\text { So,speed }=10 \frac{\text { miles }}{\text { hour }}} \\\\ {\text { speed }=10 \times \frac{1 \text { miles }}{1 \text { hour }}} \\\\ {\text { Speed }=10 \times \frac{5280 \text { feet }}{3600 \text { seconds }}} \\\\ {\text { Speed }=\frac{52800}{3600}=14.67 \mathrm{ft} / \mathrm{s}}\end{array}$

Hence, the conversions needed are 1 mile = 5280 feet and 1 hour = 3600 seconds, speed in ft/s = 14.67 ft/s