(a) The velocity ratio of the screw is 1570.8.
(b) The mechanical advantage of the screw is 785.39.
The velocity ratio of the screw is calculated as follows;
V.R = 2πr/P
where;
V.R = (2π x 0.25)/(0.001)
V.R = 1570.8
E = MA/VR x 100%
0.5 = MA/1570.8
MA = 785.39
Learn more about mechanical advantage here: https://brainly.com/question/18345299
#SPJ1