Question

Find the weight required to stretch a steel road by 2 mm, if the length of the road is 2 m and diameter 4 mm. Y= 200 GPa and g -9.8 ms2? (a) 356.4 kg (b) 295.4 kg (c) 365.4 kg (d) 256.4 kg 3.

Answer 1

Option D is the correct answer.

Step-by-step explanation:

We equation for elongation

`\Delta L=(PL)/(AE)`

Here we need to find weight required,

We need to stretch a steel road by 2 mm, that is ΔL = 2mm = 0.002 m

`A=(\pi d^2)/(4)=\frac{\pi ({4* 10^(-3)})^2}{4}=1.26* 10^(-5)m^2`

E = 200GPa = 2 x 10¹¹ N/m²

L=2m

Substituting

`0.002=(P* 2)/(1.26* 10^(-5)* 2* 10^(11))\\\\P=2520N=256.4kg`

Option D is the correct answer.