Ask Question
2 February, 11:39

Starting from rest, a disk rotates about its central axis with constant angular acceleration. In 5.00 s, it rotates 14.8 rad. During that time, what are the magnitudes of (a) the angular acceleration and (b) the average angular velocity

+1
Answers (2)
  1. 2 February, 11:57
    0
    Given:

    Initial θ = 0 rad (from rest)

    Final θ = 14.3 rad

    Time, t = 5 s

    B.

    Angular velocity, w = dθ / dt

    = (14.3 - 0) / 5

    = 2.86 rad/s

    A.

    Acceleration, ao = dw/dt

    Initial angular velocity, wi = 0 rad/s (from rest)

    Final angular velocity, wf = 2.86 rad/s

    a = (2.86 - 0) / 5

    = 0.572 rad/s^2
  2. 2 February, 15:25
    0
    (a) 1.184 rad/s²

    (b) 2.96 rad/s

    Explanation:

    (a)

    Using,

    Ф = ω₀t + 1/2αt² ... Equation 1

    Where Ф = angular distance, ω₀ = initial angular velocity, α = angular acceleration, t = time.

    Since the disk starts from rest, ω₀ = 0 rad/s,

    Therefore,

    Ф = 1/2αt²

    make α the subject of the equation

    α = 2 Ф/t² ... Equation 2

    Given: Ф = 14.8 rad, t = 5.0 s

    Substitute into equation 2

    α = 2*14.8/5²

    α = 29.6/25

    α = 1.184 rad/s²

    (b)

    Using,

    Ф = ω't ... Equation 3

    Where ω' = Average angular velocity.

    Then,

    make ω' the subject of the equation

    ω' = Ф/t ... Equation 4

    Given: Ф = 14.8 rad, t = 5.0 s

    Substitute into equation 4

    ω' = 14.8/5

    ω' = 2.96 rad/s
Know the Answer?
Not Sure About the Answer?
Get an answer to your question ✅ “Starting from rest, a disk rotates about its central axis with constant angular acceleration. In 5.00 s, it rotates 14.8 rad. During that ...” in 📙 Physics if there is no answer or all answers are wrong, use a search bar and try to find the answer among similar questions.
Search for Other Answers