Respuesta :
Answer
given,
steel wire length = 31 m
copper wire length = 16 m
diameter of both the wire = 1 mm = 0.001 m
Tension = 134 N
Density of steel = 7860 kg/m³
Density of copper = 8920 kg/m³
Speed of the wave of steel wire
[tex]v_s = \sqrt{\dfrac{T}{\dfrac{m}{l}}}[/tex]
[tex]v_s = \sqrt{\dfrac{T}{\dfrac{\rho (Al)}{l}}}[/tex]
mass = density x volume
[tex]v_s = \sqrt{\dfrac{T}{\rho A}}[/tex]
[tex]v_s = \sqrt{\dfrac{T}{\rho \pi \dfrac{d^2}{4}}}[/tex]
[tex]v_s = \sqrt{\dfrac{134}{7860 \pi \dfrac{0.001^2}{4}}}[/tex]
v_s = 147.33 m/s
Speed of the wave of copper wire
[tex]v_c= \sqrt{\dfrac{T}{\rho \pi \dfrac{d^2}{4}}}[/tex]
[tex]v_c = \sqrt{\dfrac{134}{8920 \pi \dfrac{0.001^2}{4}}}[/tex]
v_c = 138.3 m/s
time required
[tex]t = t_1 + t_2[/tex]
[tex]t = \dfrac{l_s}{v_s} +\dfrac{l_c}{v_c}[/tex]
[tex]t = \dfrac{31}{147.33} +\dfrac{16}{138.3}[/tex]
t = 0.326
