<p>A disk is initially at rest and undergoes an angular acceleration [&#945;]=2r

Question

<p>A disk is initially at rest and undergoes an angular acceleration [&#945;]=2rad/s² for 2 seconds.&#160; Abruptly teh angular acceleration becomes [&#945;]=0rad/s² and the disk continues to rotate for 3 more seconds.&#160; After these 5 seconds, the disk begins to undergo an angular deceleration of magnitude [&#945;]=4rad/s²until it comes to rest.&#160; How many rotations will the disk have turned during its entire motion.</p>

Explanation / Answer

initial angular acceleration of the disc is 1 =2rad/s^2 time t1 =2s now angular acceleration is = 0rad/s^2 time t2 =3s so angular speed is constant for this time t =5s 2 =1+t but due to initial at rest 1 =0 2 =2*5       =10rad/s if we take 2 is initial speed of the disc before go to deceleration 3^2-2^2 =2 but disk will be come to rest finally 3=0 the deceleration acceleration = -4 rad/s^2 there fore -2^2 =2(-4) angular displacement = (10)^2/8                                       =12.50 180 degree = rad 10 = /180 rad     = 0.017444 rad 12.50 =0.21805 rad but 1 revolution =2 rad 1 rad =1/2 revolutions           =0.159235 rev for 0.21805 rad = (0.21805)(0.159235) rev                           =0.034721 rev 180 degree = rad 10 = /180 rad     = 0.017444 rad 12.50 =0.21805 rad but 1 revolution =2 rad 1 rad =1/2 revolutions           =0.159235 rev for 0.21805 rad = (0.21805)(0.159235) rev                           =0.034721 rev

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.