3. Extra Credit (15 pts.) A double-threaded screw (diameter 10 mm, pitch 2 mm) is used to adjust the position of a 500-kg block as shown. Show that it's possible to lower the block by turning the...
about the vertical ()axis . (25 pts.) For the area shown, find the sentroidal moment of inertia a 9 in 9 in 3 in Centroid: 43n) 4 in 2 in 2 in (25 pts.) A 500 lb block rests on an incline as shown on the left. A cable joins it to a hanging weight W. The cable wrapstwofull turns around a cylinder plus the angle φ as shown on the right. Find the range of w for which the...
2. A square threaded power screw is used for a machine tool. The screw has 75 mm external diameter and 12 mm pitch. The operating nut takes the axial load of 550 N on a flat surface of 70 mm and 105 mm internal and external diameters respectively If the coefficient of friction is 0.16 for all contact surfaces on the nut, determine the power required to rotate the operating nut when the cutting speed is 7.5 m/min. Also find...