Walker, Halliday & Resnick — Equilibrium and Elasticity: Problem 23

23 Figure 12-30 represents an insect caught at the midpoint of a spider-web thread. The thread breaks under a stress of \(8.60 \times 10^8 \text{ N/m}^2\) and a strain of \(2.00\). Initially, it was horizontal and had a length of \(2.00 \text{ cm}\) and a cross-sectional area of \(8.00 \times 10^{-12} \text{ m}^2\). As the thread was stretched under the weight of the insect, its volume remained constant. If the weight of the insect puts the thread on the verge of breaking, what is the insect’s mass? (A spider’s web is built to break if a potentially harmful insect, such as a bumble bee, becomes snared in the web.)