A shaft made up of mild steel is required to transmit 100 kW at 300 rpm. The supported length of the shaft is 3 meters. It carries two pulleys, each weighing 1500 N, supported at a distance of 1 meter from the two ends, respectively. Assuming safe value of stress as 60 MPa, determine the minimum diameter of the shaft, required to transmit the load. A square-threaded power screw has a major diameter of 32 mm and a pitch of 4 mm with double threads, and it is to be used in an application as shown in FIGURE Q3. The given data include de = 40 mm, f=fe=0.08 and F = 6.4 kN per screw. V Collar Gear Worm Screw FIGURE Q3 Estimate the torque required to raise and lower the load. [12 marks] Determine the efficiency during lifting the load. [6 marks] [3 marks] Assess the torque to raise the load if the square thread is replaced with an ACME thread, having a thread angle of 2a. [4 marks]