Chapter 8.7, Problem 5CFU

To determine

To find: the initial horizontal velocity of a discuss.

Answer to Problem 5CFU

  $12.86\text{ meters per second}$

Explanation of Solution

Given information:

Initial velocity $\left|\overrightarrow{v}\right|=20\text{ meters per second}$

  $\left|\theta \right|=50°$

Calculation:

The initial horizontal velocity of a discuss $\left|\overrightarrow{v_x}\right|$ is evaluated as follows:

  $\begin{array}{c}\left|\overrightarrow{v_x}\right|=\left|\overrightarrow{v}\right|\cos \theta \\ =50\cos 50°\left[\text{Put the value of }\left|\overrightarrow{v}\right|\text{ and }\theta \right]\\ =12.86\text{ meters per second}\end{array}$

Thus the initial horizontal velocity is $12.86\text{ meters per second}$ .