Question

A steel wire of length 4.5 m and a copper wire of length 3.5 m are stretched same amount under agiven load. If ratio of youngs modulli of steel to that of copper is
, then what is the ratio of cross
sectional area of steel wire to copper wire ?​

Answer 1

Heya Mate

✔✅✔REFER TO ABOVE ATTACHMENT ✔✅✔

Answer 2

Answer:

Y₁ : Y₂ = 9 : 5

Explanation:

Given :

For steel wire :

A₁ = 3 × 10⁻⁵ m³  and l₁ = 4.7 m

For copper wire :

A₂ =  4 × 10⁻⁵ m³  and l₂ = 3.5 m

It is said as :

Δl₁ = Δl₂ = Δl  and  F₁ = F₂ = F

We know :

Y₁ =  F₁ l₁ / A₁ Δl₁

= > F /  3 × 10⁻⁵ × 4.7 /Δl

Also Y₂ = F₂ l₂ / A₂ Δl₂

Y₂ = F /  4 × 10⁻⁵ m³ × 3.5 / Δl

We have find ratio of Y₁ / Y₂

Y₁ : Y₂ = ( F /  3 × 10⁻⁵ × 4.7 /Δl ) / ( F /  4 × 10⁻⁵ m³ × 3.5 / Δl )

Y₁ : Y₂ = 4 × 10⁻⁵ × 4.7 / 3 × 10⁻⁵ × 3.5 )

Y₁ : Y₂ = 18.5 / 10.5 ≈ 1.8

Y₁ : Y₂ = 18 / 10 .

Y₁ : Y₂ = 9 : 5

Hence the ratio of the Young's modulus of steel to that of copper 9 : 5