Chapter 6.3, Problem 31PPS

(a)

To determine

To Find: Meter per second did she run.

Answer to Problem 31PPS

  $2.60$ meter per second

Explanation of Solution

Given:Crystal time for each portion of a triathlon are shown in the table. Round to the nearest hundredth.

  

How many meters per second did she run?

Finding the speed crystal made for the running.

  $\text{Speed=}\frac{\text{distance}}{\text{time}}$

Distance for running is $10km$

Time = $64\min$

Then

We know that

  $\begin{array}{l}1km=1000m\\ 1\min =60\sec \end{array}$

Thus

  $\begin{array}{l}\text{Speed=}\frac{\text{distance}}{\text{time}}\\ \text{Speed=}\frac{10,000}{3840}=2.60m/s\end{array}$

Hence, $2.60$ meter per second

(b)

To determine

To Find: The speed in miles per hour.

Answer to Problem 31PPS

  $12.28$ miles per hour.

Explanation of Solution

Given: Crystal time for each portion of a triathlon are shown in the table. Round to the nearest hundredth.

  

What was her speed in miles per hour for the aqua bike portion (swimming and biking)?

Total distance for aqua bike = $1.5+40=41.5$

Total time = $40+86=126$

Speed in miles per hour for the aqua bike portion is

  $\text{Speed=}\frac{\text{distance}}{\text{time}}$

We know that

  $1miles=1.609km$

Thus

  $\text{Speed=}\frac{41.5km}{126\min }=\frac{2490mi}{202.734hr}=12.28mi/h$

Hence, $12.28$ miles per hour.