If y varies inversely as x, and y =23 when x=8, find y when x=4

Agas mixture consists of 8 kmol of h2 and 2 kmol of n2. determine the mass of each gas and the apparent gas constant of the mixture.

Plot schematically the tensile stress versus strain curves for a typical thermoplastic material at a temperature below its glass transition temperature (tg and at a temperature above its tg, respectively. do the same for a typical thermosetting material. list in a table any differences or similarities between the two materials at t> tg and t < tg, respectively, and relate them to the structures of the two types of polymers

A200-mm wide strip 25 mm thick is fed through a rolling mill w/two powered rolls each of radius = 250 mm. the work thickness is to be reduced to 22 mm in one pass at a roll speed of 60 rev/min. the average flow stress of the work material, as it passes through the rolls is 175 mpa. the friction coefficient between rolls and work material is 0.20. 1, determine a)-if friction is sufficient for rolling. b)- if friction is sufficient: c)- calculate roll force i calculate roll torque. d)- calculate roll power.