A uniform rod of length L is pivoted at one end and is free to rotate in a vertical plane. A 5N force is applied in four different cases:
• Case I: Perpendicular to the rod at its free end.
• Case II: Perpendicular to the rod at its midpoint.
• Case III: At 30∘ to the rod at its free end.
• Case IV: At 30∘ to the rod at its midpoint.
Which case results in the greatest magnitude of angular acceleration of the rod immediately after the force is applied?
a) Case III
b) Case I
c) Case IV
d) Case II