Question

What force is required to stretch a steel wire of cross-sectional area 𝟑 𝒄𝒎𝟐 to double it’s length? The Young’s modulus for steel is 𝒀 = 𝟐 × 𝟏𝟎𝟏𝟏 𝑵𝒎−𝟐 .

Answer 1

$$Y=\frac{F}{eA}\\2\cdot10^{11}=\frac{F}{2(3\cdot10^{-4})}\\F=120\cdot10^{6}\ N$$