Chapter 8.2, Problem 45E

a.

To determine

To draw:a labelled diagram to show velocity and the velocity components.

Explanation of Solution

Given information:

Angle of movement towards the shore $=30°$

Velocity component towards the shore $=15\text{ mph}$

Calculation:

The diagram representing the given situation is as follows:

  

Here, $v_s$ is the component of $v_k$ towards the shore and $v_x$ is the component perpendicular to $v_s$ that needs to add up to $v_k$ .

b.

To determine

To find:the velocity.

Answer to Problem 45E

  $30\text{mph}$

Explanation of Solution

Given information:

Angle of movement towards the shore $=30°$

Velocity component towards the shore $=15\text{ mph}$

The diagram representing the given situation is as follows:

  

Calculation:

The velocity will be evaluated as follows:

  $\begin{array}{c}\sin 30°=\frac{15}{\left|\overrightarrow{v_k}\right|}\\ \left|\overrightarrow{v_k}\right|=\frac{15}{\sin 30°}\\ =30\text{ mph}\end{array}$

Thus, the velocity is $30\text{mph}$ .