Question

I need help with parts ANB of question number two

Answer 1

a.

b.

Explanation:

The change in tire's angular velocity is

`\Delta\omega=\omega_f-\omega_i`

Now,

`\begin{gathered} \omega_f=3.9\text{rad}/s \\ \omega_i=-3.9\text{rad}/s \end{gathered}`

Therefore,

`\Delta\omega=3.9-(-3.9)`

`\boxed{\Delta\omega=7.8\text{rad}/s\text{.}}`

Part B.

The average angular acceleration is given by

`\alpha_{\text{avg}}=(\Delta\omega)/(\Delta t)`

Now,

`\Delta\omega=7.8\text{rad}/s`

and

`\Delta t=1.85s`

Therefore,

`\alpha_{\text{avg}}=(\Delta\omega)/(\Delta t)=(7.8)/(1.85)`

`\Rightarrow\boxed{\alpha_{\text{avg}}=4.22\text{rad}/s^2}`

which is our answer!