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Find the greatest length of copper wire, that can hang without breaking. Breaking stress `=7.2 xx 10^(7) N//m^(2)`. Density of copper `7.2 g//c c. g=10 m//s^(2)`. |
Answer» Given, Breaking stress, `S=7.2 xx 10^(7) N//m^(2)`, Density of wire, `rho = 7.2 g//c c = 7.2 xx 10^(3) kg//m^(3)` Let l be the greatest length of wire that can hang without breaking and A be the area of cross section of the wire. Weight of wire = `(A l) rho g`. Breaking stress, `S=("weigth of wire")/("area of cross section")=(A l rho g)/(A)` or `l=(S)/(rho g) = (7.2 xx 10^(7))/((7.2 xx 10^(3)) xx 10) =1000m`. |
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