A shaft AC rotating at a constant speed carries a thin pulley of radius r = 0.4 m at the end C which drives a belt. A motor is coupled at the end A of the shaft such that it applies a torque M, about the shaft axis without causing any bending moment. The shaft is mounted on narrow frictionless bearings at A and B where AB = BC = L = 0.5 m. The taut and slack side tensions of the belt are T₁ = 300 N and T₂ = 100 N, respectively. The allowable shear stress for the shaft material is 80 MPa. The self-weights of the pulley and the shaft are negligible. Use the value of π available in the on-screen virtual calculator. Neglecting shock and fatigue loading and assuming maximum shear stress theory, the minimum required shaft diameter is mm (round off to 2 decimal places).

A mass of $$2000$$ kg is currently being lowered at a velocity of $$2$$ $$m/s$$ from the drum as shown in the figure. The mass moment of inertia of the drum is $$150$$ kg-m². On applying the brake, the mass is brought to rest in a distance of $$0.5$$ $$m.$$ The energy absorbed by the brake (in $$kJ$$) is __________________.

A drum brake is shown in the figure. The drum is rotating in anticlockwise direction. The coefficient of friction between drum and shoe is $$0.2.$$ The dimensions shown in the figure are in mm. The braking torque (in $$N.m$$) for the brake shoe is ________.

A force of $$400$$ $$N$$ is applied to the brake drum of $$0.5$$ $$m$$ diameter in a band-brake system as shown in the figure, where the wrapping angle is $${180^ \circ }$$ . If the coefficient of friction between the drum and the band is $$0.25,$$ the braking torque applied, in $$N.m$$ is