Question

A particular human hair has a Young's modulus of 3.54 × 10 9 N/m 2 and a diameter of 143 μm. If a 215 g object is suspended by the single strand of hair that is originally 19.0 cm long, by how much Δ L hair will the hair stretch? Δ L hair = m If the same object were hung from an aluminum wire of the same dimensions as the hair, by how much Δ L Al would the aluminum stretch? Δ L Al = m If the strand of hair is modeled as a spring, what is its spring constant k hair ? k hair = N/m

Answer 1

Stress & Y strain & & & A (0.21519) (9.8m) x4) = (1.54 x 18 NF42) SL 19cm T (149x105mleje AL = 0.704cm = 0.00704m hair for Aluminium Y = 690109 N/m2 sha= 0.036cm = 3.618 10m f = (YA) AL & E= kAL k = YA - (5.54 X10%) () (140x10 4232 0.19 TK = 299 Nm