Question (3) A power screw has a major diameter of 20 mm and single square threads with 4 mm pitch. The frictio coefficients are 0.075 for the threads and 0.09 for the collar that has a mean diameter of 30 mm. A lo of 5 kN is required to be raised. al Calculate the power required to raise this load if the screw is restricted to rotate at a speed of 1.5 revolution per second. b) Find overall efficiency. Question (4