Answer: 32π/9 rad/s²
Explanation: initial angular displacement = 20°, final angular displacement = 140°, average time = 2s.
We need to convert the angular displacements to radian.
Recall that 2π = 360°, hence 20° = (20 × 2π)/360 = π/9 rad
Converting 140° to radian we have that
140° = (140 × 2π)/360 = 7π/9
Initial angular displacement = π/9 rad
Final angular displacement = 7π/9
Average angular velocity = change in angular displacement /time
Average angular velocity = 7π /9 - π/9/2
Average angular velocity = (8π/9)/2
Average angular velocity = 16π/9 rad/s
Average angular acceleration = average angular velocity / time taken
Average angular acceleration = (16π/9)/2
Average angular acceleration = 32π/9 rad/s²
