o undergoes positive displacement so B NB W с / 1. 8. 2. Фи NA К» &х, Иv ХА S4 = صايم 1989 1) Ya = ļ sina 8х, -e sinoso х = l coso С. and the W and - О - о A undergo positive virtual displacements Sy and Star do negative work. Su — w Sч- P( x, -Wx l usore pollsio sol (Рg tеrs W Se ao Pesme О) «Лs p= w hotel (p= wote Ja го 6 - 0 WI use 2. в )