Question

1)

The Giant ‘Darwin’s bark spider’ (Caerostris darwini), from Madagascar spins huge capture webs that can even cross small streams (No one really knows how they do it).

A web strand 10 µ in Diameter that is 10 cm long will extend to 10.1 cm under a 0.85 gram load. What is Young’s Modulus in GPa?

2)

The typical break stress for a hair is about 250 MPa. Suppose we had a giant circular hair that was 1 inch (2.54 cm) in diameter and had this break stress (250 MPa) Approximately how many pounds of force would it take to break it? (1 N = 0.225 lbs-force)

The typical break stress for a hair is about 250 MPa. Suppose we had a giant circular hair that was 1 inch (2.54 cm) in diameter and had this break stress (250 MPa) Approximately how many pounds of force would it take to break it? (1 N = 0.225 lbs-force)

Answer 1

Da 10am a 10 x 106 2 a f = 0.85*8 mm 10 x 10 en 5x10 m, Area, AzTR² 3.14 & (5 x 10-672 = 78.5 x 10 m2 0.85 x 10 -3 9.8= 8.334 10-3 [18-9-8 megten 10 x 10 m, FA modules, Young Y 8:33 X 100/4805 210 12 Ah/ 41 210-1 -10 L = 10 em - Olen = 0.1 x 10-im. Golxi 8. 33x10 - 3 10 x 10t? - 10.61x10 Pa. 78.5810-10.1 Y = 2 10-61 GP [ Pa = rore]

- 2 27 P 2 1 2 250 MPa z 250 * 10 Pa D= 2.540m 2 2.54 107m. A - T&P= 3:4 (1024x10-32 MB 20644103 2 1.27810?m A 5.06 x 10-4 m? F = PxA = 250 x 108 x 5.06 x 100 = 1.265 x 1650 I IN= 0.25 llo aforee, F 21.265*** 0.275278.46 x 1g%26o. forec 3.