Question

An object with a mass of 70.5 kg is placed on a 2-meter strand of metal (with a 2-millimeter radius) hanging from the ceiling. It stretches 1 millimeter. What is this strand made of?

Answer 1

Based on the value of the Young's modulus, the strand of the metal is made of copper.

Young's modulus of the metal

The Young's modulus of the metal is calculated as follows;

E = stress/strain

Stress of the metal

The stress of the metal is calculated as follows;

σ = F/A = mg/A

where;

A is area of the metal

A = πr²

A = π( 2 x 10⁻³)²

A = 1.257 x 10⁻⁵ m²

σ = (70.5 x 9.8) / (1.257 x 10⁻⁵)

σ = 5.5 x 10⁷ N/m²

Strain of the metal

The strain is calculated as follows;

strain = x/L

where;

x is extension

L is original length

strain = (1 x 10⁻³ m) / 2 m

strain = 5 x 10⁻⁴

Young's modulus of the metal

E = stress/strain

E = (5.5 x 10⁷ ) / (5 x 10⁻⁴)

E = 1.1 x 10¹¹ N/m²

E = 110 Gpa

The Young's modulus of copper metal is 110 Gpa

Thus, based on the value of the Young's modulus, the strand of the metal is made of copper.

Learn more about Young's modulus here: brainly.com/question/6864866