Chapter 4, Problem 38CLR

To determine

To calculate: the distance between Randy and Amy after 10minuntes.

Answer to Problem 38CLR

They are 1.2 km apart after 10 minutes

Explanation of Solution

Given information: Randy and Amy walk in opposite directions at the same time,

Speed of Randy, $v_R$ =3.6 km/hr, Speed of Amy, $v_A$ = 4.2km/h, Time, $t$ = 10min

Formula used: $SPEED=\frac{DISTANCE}{TIME}$ , km/hr

Calculation:

Time, $t$ = 10min= $\frac{10}{60}=\frac{1}{6}$ hr

Distance travelled by Randy ( $d_R$ ) in 10 minutes,

  $\begin{array}{l}{v}_R=\frac{d_R}{t}\\ \Rightarrow d_R=v_R\times t\\ \Rightarrow d_R=3.6\times \frac{1}{6}\\ \Rightarrow d_R=0.6km\end{array}$

Again, Distance travelled by Amy ( $d_A$ ) in 10 minutes,

  $\begin{array}{l}{v}_R=\frac{d_A}{t}\\ \Rightarrow d_A=v_A\times t\\ \Rightarrow d_A=4.2\times \frac{1}{6}\\ \Rightarrow d_A=0.7km\end{array}$

Since both of them are walking in opposite directions,

Therefore, The total distance between them= $d_A+d_R$

= $0.7+0.6=1.2km$

Thus, they are 1.2 km apart after 10 minutes.