A polyster fibre rope of diameter 3cm has a breaking strength of 150kN. If it is required to have 600kN breaking strength. What should be the diameter of similar rope?

Options

A. 12cm
B. 6cm
C. 3cm
D. 1.5cm

Answer

B

Explanation

`Y = (FL)/(A Delta L)`
The braking strength `F prop A`
`:. (F_(2))/(F_(1)) = (A_(2))/(A_(1)) = (pi D_(2)^(2)//4)/(pi D_(1)^(2) //4) = (D_(2)^(2))/(D_(1)^(2))`
or `D_(2) = D_(1) ((F_(2))/(F_(1)))^(1//2) = 3 ((600)/(150))^(1//2) = 6cm`