... dinh r6c d0 cua mQt nguOn Am bing cdch sri dpng thi6 t bi do.tAn sO am Kl'ti ;.^,i nguon am cnuyerl odng thing d€u lpi gAn iniet bi dang dimg y6n thi thitit b! duqc tdn sd irn Ib,124 H7, cdn ngu6n ... dm-chuy€"n dqng th"ing ddu vdi cirng toc dg d6 xa thi6 t bi thi thi€t bi.do dirgc tAn sO am le 606-ltz.Biet.rrguOn am ia rhielbi lu6n cirng nim tr€n mQt ducrng thing, tAn s0 cua nguOn 6m phdtra lh kh6ng ... 50) Cfru 41 Trong qu6 trinh dao dQng, chidu dli cta lic ld xo treo thing dung bii5n thi6 n ttr 30 cm Khi lb xo c6 chi0u dei 40 cm thi B pha dao dQng cua vdt bing A tdc dQ cria vdt cuc D gia t6c ctra...