Inspired by your favourite physics course, you decide to build a bookshelf, supported by nylon fishing line cables as illustrated. When the shelf is fully loaded with books, the tension in each cable is 30 N. You opt for cable with a diameter of 0.5 mm, and the cables are 45 cm long when unstressed.
The Young's modulus for nylon fishing line is around 2.0 G Pa, i.e. $2.0 \times 10^9$ Pa
Express all answers correct to at least 2 significant figures. Remember you can enter numbers in scientific notation, e.g. $1.9 \times 10^8$ is typed 1.9e8 and $9.5 \times 10^{-6}$ is typed 9.5e-6
1. What is the cross-sectional area of the cable? A =
2. What is the stress on the cable?