Respuesta :

Answer:  The answer is:  " 322.7  ft. "

_______________________________

Step-by-step explanation:

First:

Convert:  " 22 mi /h" ; to:  " ft / s " ;

______________________

Note the following exact conversions:

______________________

1 mi = 5280 ft. ;

1 h = 60 min.

1 min = 60 s ;

______________________

[tex]\frac{22 mi}{h} *\frac{5280ft}{mi} *\frac{1 h}{60 min}*\frac{1 min}{60 s}[/tex] =  ? ft/sec. ?

______________________

From the "left-hand side" of the equation:

_____________________

1) The units of "mi" ["mile(s}"] cancel out; since:  "mi/mi" = 1 .

_____________________

2) The units of "h" ["hour(s)"] cancel out; since:  "h/h" = 1 .

_____________________

3) The units of "min" ["minute(s)"] cancel out; since:  "min/min" = 1.

_____________________

And we are with units of "ft/s" ["feet per second"] :

_____________________

→  " [tex](\frac{22*5280}{60*60}) \frac{ft}{s}[/tex] ";  Using calculator:

_____________________

           = " [tex](\frac{116160}{3600}) \frac{ft}{s}[/tex] " ;  Using calculator:

______________________

           = " [tex]32.2666666667 \frac{ft}{sec}[/tex] " ;

_____________________

Now, we are asked:

_____________________

"How many feet will it cover in 30 seconds?"

_____________________

  To solve:

______________________

  " [tex]\frac{32.2666666667 ft}{s} *\frac{10 s}{1 } = ? ft[/tex] " ;

______________________

Note: The units of "s" ["second(s)"] on the "left-hand side" of the equation; cancel out to "1" ; since:  "s/s" = 1 ;  

______________________

And we have:

______________________

 " ( [tex]32.2666666667 * 10[/tex] ) ft ;

________________________

       →  [tex]= 322.666666667[/tex] ft ;

 {Note:  To multiply by "10"; move the decimal one space to the right; or use calculator to get the value;

________________________

Second:

→  We are asked to round our answer to the "nearest tenth of a foot" ;

_________________________

 We have:  " 322.666666.... ft." :

__________________________

Note:  "322.666..."

 The "tenths" place has a digit of "6".

__________________________

The question is:  To round to the nearest tenth:

Do we round to "322.6" ? or round up to: "322.7" ?

To determine this, we examine the next following decimal; that is,

the "hundredths" place.  

 If the digit within the hundredths place is:  "0, 1, 2, 3, or 4" ; then, we "round down" to "322.6 ".

 If the digit within the hundredths place is:  "5, 6, 7, 8, or 9" ; then, we "round up" to "322.7 ".

___________________________

In our case, the digit within the hundredths place is "6" ;

 As such, we round to: "322.7" .

___________________________

The answer is:  " 322.7  ft. "

___________________________

Hope this answer—and explanation—is helpful to you!

___________________________