Assignment

1. Determine the rigidity modulus of Zinc wires of radii 0.4 mm and 0.7 mm, and show that it is independent of radius.
2. Find the ratio of time periods of two identical torsion pendulums with moment of inertia I₁ = 25 × 10^–4 kg·m² and I₂ = 12.5 × 10^–4 kg·m².
3. Find the rigidity modulus of the copper wire of radius 0.5 mm and length 60 cm.
4. Find the moment of inertia of a given disc of mass 1.5 kg and radius 7 cm.
5. Find both the moment of inertia of the disc and the rigidity modulus of a Zinc suspension wire.
   Given: radius and length of the suspension wire are 0.6 mm and 60 cm.
   Take the mass and radius of the disc as 1.5 kg and 7 cm respectively.