Answer:
[tex]\alpha =-38.22\ rad/s^2[/tex]
Explanation:
given,
ω(t) = 2.00 rad/s- 2.1.00 rad/s³ t²
angular acceleration of the blade at t= 9.10 s
[tex]\alpha =\dfrac{d\omega}{dt}[/tex]
[tex]\alpha =\dfrac{d}{dt}(2 - 2.1 t^2)[/tex]
[tex]\alpha =-2 \times 2.1 t[/tex]
[tex]\alpha =-4.2 t[/tex]
angular acceleration of blade at t = 9.10
[tex]\alpha =-4.2\times 9.10[/tex]
[tex]\alpha =-38.22\ rad/s^2[/tex]