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Q3. An engine room lift cage has a mass of 1 tonne. The hoist wire is wound around a motor driven drum, with the lift cage on one end and a balance mass of 0.8 tonne suspended from the other end. The drum is 1.4 m diameter with a mass of 250 kg and radius of gyration of 450 mm.

The maximum tension in the hoist wire is not to exceed 12 kN. Calculate EACH of the following:

(a) The maximum allowable acceleration of the lift cage when being raised;

(b) The driving torque required at the drum to achieve the acceleration found in part Q2(a);

(c) The motor output power when the lift is moving upwards with a constant velocity of 3 m/s.