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A car engine is initially rotating at 250 rad/s. It is then turned off and takes 4.80 s to come to a complete stop. What is the angular acceleration of the engine

Respuesta :

Answer:

[tex]\alpha = 52.1[/tex]

Explanation:

Given

[tex]w_1 = 250\ rad/s[/tex] --- initial angular velocity

[tex]t_2 = 4.8s[/tex] -- Initial time

Because the engine completely stops, we have the following:

[tex]w_2 = 0\ rad/s[/tex]  --- final angular velocity

[tex]t_1 = 0[/tex] --- final time

Required:

Determine the angular acceleration ([tex]\alpha[/tex])

The angular is calculated as thus:

[tex]\alpha = \frac{w_2 - w_1}{t_2 - t_1}[/tex]

i.e. the ratio of change in angular velocity to change in time

Substitute in the required values, the expression becomes:

[tex]\alpha = \frac{250 - 0}{4.8 - 0}[/tex]

[tex]\alpha = \frac{250}{4.8}[/tex]

[tex]\alpha = 52.08333[/tex]

[tex]\alpha = 52.1[/tex] -- approximated

Hence, the engine's angular acceleration is 52.1rad/s^2