Answer:
1.805 mm
Explanation:
Extension in the steel wire = WL_{steel}/AE_{steel}
Extension in the aluminium wire = WL_{Al}/AE_{Al}
Total extension = W/A * (L_{steel}/E_{steel} + L_{Al}/E_{Al})
we have:
W = mg
W = 5 × 9.8
W = 49 N
Area A = π/4 × (0.001)²
= 7.85398 × 10 ⁻⁷ m²
Total extension = W/A * (L_{steel}/E_{steel} + L_{Al}/E_{Al})
Total extension = 49/ 7.85398 × 10 ⁻⁷ ( (1.5/ 200×10⁹) + 1.5/ 70×10⁹))
Total extension = 0.0018048
Total extension = 1.805 mm
Thus, the total extension = the resulting change in the length of this composite wire = 1.805 mm
