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solid disk at rest starts to spin. The angular acceleration is constant.After 3 revolutions the wheel is spinning at 6radsec. Find the linear velocity andacceleration of a point on the disk 1.2 meters away from the center (axis) at20 seconds.

Respuesta :

Answer:

Explanation:

Given,

Angular displacement, θ = 3 rev

                                         = 3 x 2π = 6π

initial angular speed, ω = 0 rad/s

Angular speed when disk is revolved to 3 revolution = 6 rad/s

radius, r = 1.2 m

time, t = 20 s

Calculating angular acceleration

[tex]\omega^2 = \omega_0^2 +2 \alpha \theta[/tex]

[tex](6)^2= 0 +2 \alpha\times (6\pi)[/tex]

[tex]\alpha = 0.955\ rad/s^2[/tex]

Acceleration of the disk

[tex]a = \alpha R[/tex]

[tex]a =0.955\times 1.2 = 1.146\ m/s^2[/tex]

Now for linear velocity calculation

[tex]\omega = \omega_0 + \alpha t[/tex]

[tex]\omega =0 +0.955\times 20[/tex]

[tex]\omega = 19.1\ rad/s[/tex]

Linear velocity,

[tex]v = r \omega[/tex]

[tex]v = 1.2 \times 19.1[/tex]

[tex]v = 22.92\ m/s[/tex]