Chapter 4.2, Problem 65SR

To determine

Graph: Sketch the graph of the equation.

Explanation of Solution

Given: The distance $d$ in miles that the sound of thunder travels in time $\left(t\right)$ is given as,

  $d=0.21t$

Graph:The distance $d$ in miles that the sound of thunder travels in time $\left(t\right)$ is given as $d=0.21t$ . If on plotting time $\left(t\right)$ on $x-axis$ and distance $\left(d\right)$ on $y-axis$ thenfor different values of time $\left(t\right)$ the obtained values of $\left(d\right)$ are evaluated as,

t	0	2
d	0	0.42

On joining the points $\left(0,0\right)$ and $\left(2,0.42\right)$ the graph of the line is plotted as,

  

Interpretation: The graph of the equation is a straight line passing through the points $\left(0,0\right)$ and $\left(2,0.42\right)$ .

To determine

Using graph evaluate the time $\left(t\right)$ that will be taken to hear thunder from a storm 3 miles away.

Answer to Problem 65SR

From the graph it will take around 14.3 seconds to hear thunder from a storm 3 miles away.

Explanation of Solution

Given: The distance $d$ in miles that the sound of thunder travels in time $\left(t\right)$ is given as,

  $d=0.21t$

Calculation: From the graph as in sub-part $a$ it will take around 14.286 seconds to hear thunder from a storm when 3 miles away as shown in graph.