Answer
given,
diameter of steel = d = 26 c m
Ā Ā Ā Ā Ā radius = 13 cm = 0.13 m
length = L = 2.4 m
mass = 7800 Kg
g = 9.8 m/sĀ²
a) stress = F/A
stress = [tex]\dfrac{mg}{\pi\ r^2}[/tex]
stress = [tex]\dfrac{7800 \times 9.8}{\pi\ 0.13^2}[/tex]
stress = 1.44 x 10ā¶ N/mĀ²
b) Young's modulus x Ā strain = stress
Ā Young's modulus for steel = 200 x 10ā¹ N/mĀ²
Ā Ā 200 x 10ā¹ x strain = 1.44 x 10ā¶
Ā Ā Ā strain = 7.2 x 10ā»ā¶ m
c) change in length
Ā [tex]Strain= \dfrac{\Delta L}{L}[/tex]
Ā [tex]7.2 \times 10^{-6} = \dfrac{\Delta L}{2.4}[/tex]
Ā [tex]\Delta L= 17.28\times 10^{-6}\ m[/tex]
