Average angular acceleration (8-14)

Question 1 of 3

Question

$\textbf{Elapsed time}$ for the time interval: The object has angular velocity $\omega_{1z}$ at time $t_1$ , and has angular velocity $\omega_{2z}$ at time $t_2$ .

{"title":"Average angular acceleration of a rotating object","description":"Wrong","type":"incorrect","color":"#99CCFF","code":"[{\"shape\":\"poly\",\"coords\":\"82,133\"},{\"shape\":\"rect\",\"coords\":\"1,23,21,50\"}]"} {"title":"Change in angular velocity of the object over a certain time interval: The angular velocity changes from omega sub 1z to omega sub 2z","description":"Incorrect","type":"incorrect","color":"#ffcc00","code":"[{\"shape\":\"rect\",\"coords\":\"118,11,119,13\"},{\"shape\":\"rect\",\"coords\":\"159,8,181,22\"},{\"shape\":\"rect\",\"coords\":\"250,5,273,29\"}]"} {"title":"Elapsed time for the time interval: The object has angular velocity omega sub 1z at time t sub 1, and has angular velocity omega sub 2z at time t sub 2.","description":"Correct!","type":"correct","color":"#333300","code":"[{\"shape\":\"rect\",\"coords\":\"154,41,183,53\"},{\"shape\":\"rect\",\"coords\":\"258,39,281,60\"}]"}

Question

$\textbf{Average angular acceleration}$ of a rotating object

{"title":"Average angular acceleration of a rotating object","description":"Correct!","type":"correct","color":"#99CCFF","code":"[{\"shape\":\"poly\",\"coords\":\"82,133\"},{\"shape\":\"rect\",\"coords\":\"1,23,21,50\"}]"} {"title":"Change in angular velocity of the object over a certain time interval: The angular velocity changes from omega sub 1z to omega sub 2z","description":"Wrong","type":"incorrect","color":"#ffcc00","code":"[{\"shape\":\"rect\",\"coords\":\"118,11,119,13\"},{\"shape\":\"rect\",\"coords\":\"159,8,181,22\"},{\"shape\":\"rect\",\"coords\":\"250,5,273,29\"}]"} {"title":"Elapsed time for the time interval: The object has angular velocity omega sub 1z at time t sub 1, and has angular velocity omega sub 2z at time t sub 2.","description":"Incorrect","type":"incorrect","color":"#333300","code":"[{\"shape\":\"rect\",\"coords\":\"154,41,183,53\"},{\"shape\":\"rect\",\"coords\":\"259,38,282,59\"}]"}

Question

$\textbf{Change in angular velocity}$ of the object over a certain time interval: The angular velocity changes from $\omega_{1z}$ to $\omega_{2z}$

{"title":"Average angular acceleration of a rotating object","description":"Wrong","type":"incorrect","color":"#99CCFF","code":"[{\"shape\":\"poly\",\"coords\":\"82,133\"},{\"shape\":\"rect\",\"coords\":\"1,23,21,50\"}]"} {"title":"Change in angular velocity of the object over a certain time interval: The angular velocity changes from omega sub 1z to omega sub 2z","description":"Correct!","type":"correct","color":"#ffcc00","code":"[{\"shape\":\"rect\",\"coords\":\"118,11,119,13\"},{\"shape\":\"rect\",\"coords\":\"159,8,181,22\"},{\"shape\":\"rect\",\"coords\":\"250,5,273,29\"}]"} {"title":"Elapsed time for the time interval: The object has angular velocity omega sub 1z at time t sub 1, and has angular velocity omega sub 2z at time t sub 2.","description":"Incorrect","type":"incorrect","color":"#333300","code":"[{\"shape\":\"rect\",\"coords\":\"154,41,183,53\"},{\"shape\":\"rect\",\"coords\":\"258,39,281,60\"}]"}

Review

Suppose a rigid object is rotating around the $z$ axis with angular velocity $\omega_{1z}$ at time $t_1$ and with angular velocity $\omega_{2z}$ at a later time $t_2$ (Figure 8-15). The $\textbf{average angular acceleration}$ $\alpha_{\mathrm{average},z}$ (the Greek letter $\alpha$ , or alpha) for the time interval between $t_1$ and $t_2$ is the change in angular velocity, $\Delta{\omega_z} = \omega_{2z} - \omega_{1z}$ divided by the duration of the time interval, $\Delta{t} = t_2 - t_1$ :