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Q2. A Porter governor has arms of equal length, three flyweights each of mass 3 kg and a central mass of 18 kg. Friction at the sleeve is constant at 22 N.

Calculate the maximum and minimum speeds for a governor height of 120 mm.

Q4. A hollow propeller shaft of 380 mm outside diameter and 320 mm inside diameter runs at 90 rev/min and propels a ship through the water at 17 knots. The total resistance of the ship through the water at this speed is 300 kN and the propeller efficiency is 78%. Calculate EACH of the following:

(a) the power transmitted by the shaft;

(b) the angel of twist of the shaft per metre length in degrees;

(c) the maximum torsional stress in the shaft.

Note: Modulus of Rigidity of Shaft Material 80 GN/m².

1 knot = 0.514 m/s

Q2. An “I” section beam as shown in Fig Q4 is simply supported at both ends. It carries a uniformly distributed load of 6 kN/m along its entire length and has a concentrated load of 18 kN at mid-span. The safety coefficient (factor of safety) of the beam is limited to 4.

Determine the maximum permissible length of the beam.

Note: UTS of Beam Material = 120 MN/m²

Q4. When subjected to a tensile load of 80 kN, a uniform metal rod 30 mm diameter and 3 m long extends by 1.8 mm. The unloaded rod is then placed vertically with its upper end fixed and a collar fitted at its free lower end. A load mass is then allowed to drop onto the collar from a height of 180 mm, and the instantaneous extension of the rod is found to be 3.6 mm. Calculate EACH of the following:

(a) the Modulus of Elasticity for the rod;

(b) the magnitude of the load mass.