A motorcycle, which has an initial linear speed of 8.0 m/s, decelerates to a speed of 2.2 m/s in 4.1 s. Each wheel has a radius of 0.60 m and is rotating in a counterclockwise (positive) directions. What is
(a) the constant angular acceleration (in rad/s2) and
(b) the angular displacement (in rad) of each wheel?

Respuesta :

Answer:

Explanation:

Given

Initial linear speed [tex]v_1=8 m/s[/tex]

initial angular velocity [tex]\omega _1=\frac{v_1}{r}=\frac{8}{0.6}=13.33 rad/s[/tex]

Speed after 4.1 s is  [tex]v_2=2.2 m/s[/tex]

[tex]\omega _2=\frac{2.2}{0.6}=3.66 rad/s[/tex]

using [tex]\omega _2=\omega _1+\alpha t[/tex]

where [tex]\alpha [/tex]is angular acceleration

[tex]3.66=13.33+\alpha \cdot 4.1[/tex]

[tex]\alpha =-2.37 rad/s^2[/tex] i.e. clockwise

(b)angular displacement

[tex]\theta =\omega _1t+\frac{\alpha t^2}{2}[/tex]

[tex]\theta =13.33\times 4.1-\frac{2.37\cdot 4.1^2}{2}[/tex]

[tex]\theta =54.66-19.75[/tex]

[tex]\theta =34.91 rad[/tex]