Chapter 6.3, Problem 31PPS

(a)

To determine

To Calculate: The rate of her run in meter per second.

Answer to Problem 31PPS

2.60 meter per second

Explanation of Solution

Given information: Table with information about the distance and time taken.

Calculation: Crystal run 10 kilometers in 64 minutes. We need to convert kilometer into meters and minutes into seconds.

We know that, $\begin{array}{l}1\min ute=60\sec onds\\ 1km=1000m\end{array}$

Convert $\frac{10km}{64\min }$ into $\frac{meter}{\sec ond}$

  $\begin{array}{l}\frac{10km}{64\min }·\frac{1\min }{60\sec }·\frac{1000m}{1km}=\frac{10·1000}{64·60}\frac{m}{s}\\ 2.60\frac{m}{s}\end{array}$

Crystal ran 2.60 meter per second

(b)

To determine

To Calculate: The rate of her swimming and biking in miles per hour

Answer to Problem 31PPS

Crystal’s speed is 12.27 miles per hour.

Explanation of Solution

Given information: Table with information about the distance and time taken for swimming and biking.

Calculation: Crystal swims 1.5 kilometers in 40 minutes and biking was 40 km in 86 minutes. We need to convert kilometer into miles and minutes into hour.

First we add the kilometers she swims and bike and also we add the time as well.

  $\begin{array}{l}1.5+40=41.5km\\ 40+86=126\min \end{array}$

We know that, $\begin{array}{l}1hour=60\min utes\\ 1km=0.621miles\end{array}$

Convert $\frac{41.5km}{126\min }$ into $\frac{miles}{hour}$

  $\begin{array}{l}\frac{41.5km}{126\min }·\frac{60\min }{1hr}·\frac{0.621mi}{1km}=\frac{41.5·60·0.621}{126}\frac{mi}{hr}\\ 12.27\frac{mi}{hr}\end{array}$

Crystal’s speed is 12.27 miles per hour.