AP EAMCET201921 Apr 2019Evening ShiftPhysicsMotion in Two DimensionsActual
A uniform rod of length l and density ρ is revolving about a vertical axis passing through its one end. If ω is the angular velocity of the rod then the centrifugal force per unit area of the rod is
Options
- Aρ ω 2 l 2 4
- Bρ ω 2 l 2 12
- Cρ ω 2 l 2 2
- Dρ ω 2 l 2 8
Correct answer
C. ρ ω 2 l 2 2
Step-by-step solution
Take an element of length d x and mass d m at a distance x from the rotating end. Here mass of elemental part d m = ρ d x Centrifugal force on this small element d F = d m   x ω 2 Total centrifugal force, F = ∫ d F = ∫ 0 l ρ x ω 2 d x ⇒     F = ρ ω 2 l 2 2