A motorcycle, which has an initial linear speed of 7.1 m/s, decelerates to a speed of 1.9 m/s in 6.0 s. Each wheel has a radius of 0.65 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 :

Explanation:

Given that,

Initial linear speed of the motorcycle, u = 7.1 m/s

Final linear speed of the motorcycle, v = 1.9 m/s

Radius of the wheel, r = 0.65 m

Time, t = 6 s

(a) Let a is the linear acceleration. It can be calculated as :

[tex]a=\dfrac{v-u}{t}[/tex]

[tex]a=\dfrac{1.9-7.1}{6}[/tex]

[tex]a=-0.86\ m/s^2[/tex]

If [tex]\alpha[/tex] is the angular acceleration. The relation is given by :

[tex]\alpha =\dfrac{a}{r}[/tex]

[tex]\alpha =\dfrac{-0.86}{0.65}[/tex]

[tex]\alpha =-1.32\ rad/s^2[/tex]

(b) Let d is the linear displacement.

[tex]d=\dfrac{u+v}{2}\times t[/tex]

Let [tex]\theta[/tex] is the angular displacement

[tex]\theta=\dfrac{d}{r}=\dfrac{\dfrac{u+v}{2}\times t}{r}[/tex]

[tex]\theta=\dfrac{\dfrac{7.1+1.9}{2}\times 6}{0.65}[/tex]

[tex]\theta=41.53\ rad[/tex]

Hence, this is the required solution.