Question

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 block is in equilibrium Assume a coefficient of static friction of 0.3. T/T- 2. 500 Ib /2 40° 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 screw (that is, show that there isn't too much friction between the block and the incline). What minimum torque applied to the screw is required to lower the block down the incline? Assume a coefficient of static friction of 0.3 between all surfaces. 3. 500 kg 35°

Answer 1

21) MO 12 dm = I2-- 1ル 12 4서 2 In 12 dA - 35 12 12

うし 13 莊9 12)) 3 3 56 1m 3 518.399 1xx 잣 5,8399 07 999

gum 21-n TT R τ4.sai*) 지 3TT 2 31 3厅 3

1447 ,952 im у 2 3 6

2 ·Ti LW Rr) Soo 1300 2-40 180 0.3x2,268 36.299
Insufficient time for solving 3 rd one