Mechanics of Solids | Solved Problems | Part 2 | Complementary Physics | BSc | Kerala University

This video contains solved problems from the chapter Mechanics of solids.

1. A wire of radius 1 mm and length 2 m is twisted through 90^0. Calculate the angle of shear at the surface, at the axis of the wire and at a point mid way. If the modulus of rigidity of the material is 5×10^10 𝑁𝑚^(−2), what is the torsional couple.
2. An iron wire of radius 1 mm and length 100 cm is twisted through an angle 18^0. Find the maximum angle of shear. If the rigidity modulus of iron is 8×10^10 𝑁𝑚^(−2), what is the torsional couple?
3. Two cylinder A and B of radii r and 2r are soldered co axially. The free end of A is clamped and the free end of B is twisted by an angle 𝜃. Calculate the twist at the junction taking the material and length of the two cylinders same.
4. What couple must be applied to a wire 1 m long and 3 mm diameter to twist one end through 45^0, while the other end fixed. Rigidity modulus of wire is 5×10^10 𝑁𝑚^(−2).
5. A wire of length 1m and diameter 10^(−3) 𝑚 fixed at one end is twisted through 70^0 by a force of 5×10^(−3) 𝑘𝑔 𝑤𝑡 applied to each end of 0.2 m length rod soldered at its middle point to the other end of the wire. Calculate the rigidity modulus of the wire.
6. A metal disc of diameter 0.1 m and mass 1.2 kg is fixed symmetrically to the lower end of a torsion wire of length 1m and diameter 1.44×10^(−3)m, the upper end is fixed. The time period of torsional oscillation is 1.98 s. Calculate the rigidity modulus of the material of the wire.

By
Rejeena R Sebastian
Department of Physics
St Xavier's College