Chapter 8. Average angular acceleration (8-14)

Question

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{"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

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{"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\"}]"}

Question

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{"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\"}]"}

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, \(\Delta{t} = t_2 - t_1\):