A wire of length L is made up of two sections of two different materials connected in series. The first section of length L1 = 17.7 m is made of steel and the second section of length L2 = 28.5 m is made of iron. Both wires have the same radius of 5.30 ✕ 10−4 m. If the compound wire is subjected to a tension of 148 N, determine the time taken for a transverse pulse to move from one end of the wire to the other. The density of steel is 7.75 ✕ 103 kg/m3 and the density of iron is 7.86 ✕ 103 kg/m3.

Explanation:

velocity of wave in a tense wire is given by the expression

v is velocity . T is tension and m is mass per unit length .

for steel wire

m = π r² ρ where r is radius and ρ is density

= 3.14 x (5.3 x 10⁻⁴)²x7.75 x 10³

= 683.57 x 10⁻⁵ kg/m

v =  

= 1.47 x 10² m /s

= 147 m /s

for iron  wire

m = π r² ρ where r is radius and ρ is density

= 3.14 x (5.3 x 10⁻⁴)²x7.86 x 10³

= 693.27 x 10⁻⁵ kg/m

= 146 m /s

Time taken to move from one end to another

= 17.7 / 147 + 28.5 / 146

= .12 + .195

= .315 s .

i think it’s a. this is because if they measured the mass of something with a mass of 150g, then their final answer would have to be approximately 150g. though all of their answers are almost 150, rosa and tran have the closest answers (or the exact answer) to the accurate one.

grav forces affect all objects magnetic forces affect magnetic objects and electric currents