Questions and Answers - Unstretched Length of Wire

is when the tension is T, & ? The length of a metalcine and l2 when the tesion is T2-The unstreeched length of Cuire is Oar ans : L, Tr L2 T2 L,A Y= stress = case J = x II/A = Strain (Lrl) / i TiL A(L,L-L), Casez = Y= T2L A(L2-L) TiL = T2L A(L,L-L) A(L2-L) II = T2 Li-L L2-L TIL2 - TL T2 L,-T2L L (T2-T1) = T2L, TxL2

?Steel wire with cross section 3cm has elastic limit 2,4x 10 N/M

The maximum unward accele- ration that can be given to a 1000 1200 kg elevator supported by this able wire. if the stressis not to exceed a / /3rd of the clastic limit? ans: 2.4x108rmm2 , 1200kg F= 1/3 X (2.4x108) x 3x 104 F = m (g+a) 24 2.4 x 10" N =