Question

-2
-3
If
find
14. A substance breaks down by a stress of 10'Nm
the density of the substance be 3 x 103 kg m
that length of the wire made of the same substance,
by which it will break under its own weight when
suspended.
Ans. 3.4 x 104 m.
106
-2
N​

Answer 1

Answer:

Stress = F/A = {(M ∙ g) / A} (1)

∵ density = [{mass} / {volume}]

ρ = {M / (A ∙ L)} i.e. M = ρAL

∴ from (1)

Stress = {(ρAL ∙ g) / A}

Stress = ρ ∙ L ∙ g

Given : stress = 106 N/m2

ρ = 3 × 103 kg/m3

Hence

106 = 3 × 103 × L × 10

∴ {106 / (3 × 104)} = L

∴ L = (100 / 3)

L = 33.3 m

Answer 2

Answer:

3.3x10^4.

U can get correct answer by placing the value of g as(9.8)