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The speed of a longitudinal wave in a metallic bar is 400 m/s. If the density and Young's modulus of the bar material are increased by 0.5% and 1%, respectively then the speed of the wave is changed approximately to m/s.
(3) 401
v = Y
vv 100 = 12 ( YY 100 - 100 )
= 12(1\% - 0.5\%) = 0.25\%
v = 0.25\% 400 = 1 m/s
v' = 400 + 1 = 401 m/s
Answer: (3)
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