A cylinder contains 480 cm3 of loose dry sand which weighs 820 g. Under a static load of 200 kPa the volume is reduced 1%, and then by vibration it is reduced 10% of the original volume. Assume the solid density of sand grains is 2.65 Mg/m3 . Compute the void ratio, porosity, dry density, and total density corresponding to each of the following cases:.(a) Loose sand. (b) Under static load. (c) Vibrated and loaded sand.

a.

b.

c.

Explanation:

a. void  ratio is provided by the formula:

   where , = volume of voids

                = volume of solid grains

for loose sand, the void space =

                                                   = 1

b. void ratio after static load = 0.1/(480)/ (480)

                                               = 0.1

c. void ratio after vibration = [480- ( 0.1 * 480) ]/ 480

                                             = 0.9

diy

explanation:

unlike the threaded fasteners which are used to clamp the machine members, power screws are used to transmit power. common applications of power screws are: screw jacks: to lift weight. lead screw of lathe: for axial movement of tool and its precise positioning.