An 800-kg mass is hung from a 1.5-m copper wire with a cross-sectional area of 0.35 cm².Young's modulus for copper is 1.1 $\times$ 10¹¹ N/m².How much does the wire stretch? A)2.56 mm B)2.97 mm C)3.14 mm D)3.86 mm E)4.13 mm

Question

Quizplus · Accepted Answer

First, we need to calculate the cross-sectional area in square meters:
0.35 cm² = 0.35 × 10⁻⁴ m²
Next, we can use the formula for the elongation of a uniformly loaded wire:
ΔL = FL/AY
where ΔL is the elongation, F is the force applied, L is the original length of the wire, A is the cross-sectional area, Y is Young's modulus.
Substituting the given values:
ΔL = (800 kg × 9.81 m/s²) × 1.5 m / (0.35 × 10⁻⁴ m² × 1.1 × 10¹¹ N/m²)
ΔL ≈ 0.00386 m = 3.86 mm
Therefore, the wire stretches by 3.86 mm. The correct answer is D).

An 800-Kg Mass Is Hung from a 1 ×\times× 1011 N/m2

An 800-Kg Mass Is Hung from a 1 $\times$ 10¹¹ N/m²