Evaluate elongation of wire, Mechanical Engineering

Assignment Help:

Evaluate Elongation of wire:

An aerial copper wire (E =1 x 105 N/mm2) 40 m long is having cross sectional area of 80 mm2 and weighs 0.6 N per meter run. If wire is suspended vertically, calculate

(a) Elongation of wire because of self weight,

(b) Total elongation when a weight of 200 N is attached to the lower end of it, and

(c) Maximum weight which this wire can support at the lower end if limiting value of stress is 65 N/mm2.

Sol.:  (a) Weight of wire W = 0.6 × 40 = 24 N The elongation because of self weight is,

δL =   L2/2 E; where ω  is the specific weight (weight per unit volume)

In the terms of total weight W =       ωAL

δL = WL2/E = 24 × (40 × 103)/2 × 80 × (1 × 105)

= 0.06 mm                                                                               .......ANS

(b) Extension because of weight P attached at lower end,

δL = PL/2E

= 200 × (40 × 103)/80 × (1 × 105)

= 1.0 mm

Total elongation of wire = 0.06 + 1.0 = 1.06 mm

(c) Maximum limiting stress = 65 N/ mm2

Stress because of self weight equals that produced by a load of half its weight applied at the end. That is

Stress because of self weight = (W/2)/A = (24/2)/80 = 0.15 N/ mm2

Remaining stress = 65 - 0.15 = 64.85 N/mm2

Maximum weight that the wire can support = 64.85 × 80 = 5188 N


Related Discussions:- Evaluate elongation of wire

Key words related to air transportation, Keywords related to Air transporta...

Keywords related to Air transportation: Airfield/Airport       :            The area which contains the facilities needed for the operation of aircraft. Apron

Enumerate about the loading conditions, Loading Conditions Non-uniformi...

Loading Conditions Non-uniformity of loading has to be considered in the choice of foundations particularly in highly compressible soils. It is not uncommon for buildings with

Thermodynamics, What is the concept of continuum? How will you define densi...

What is the concept of continuum? How will you define density and pressure using this concepts

Fatigue loading on materials, what are the factors that affecting the fatig...

what are the factors that affecting the fatigue behaviour of materials?

Input tolerance of motor, Motor shall operate successfully at rated load wi...

Motor shall operate successfully at rated load with a voltage variation of plus or minus ten percent and frequency variation of plus or minus five percent, or combined variation of

Evaluate force and moment - mechanics, Evaluate force and moment: Wha...

Evaluate force and moment: What force and moment is transmitted to supporting wall at A   A force of 15 KN is transmitted to wall along with anticlockwise mome

Shielding gases, SHIELDING GASES Shielding gas is directed by the to...

SHIELDING GASES Shielding gas is directed by the torch to the arc and weld pool to protect the electrode and the molten weld metal from atmospheric contamination.  Argon

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd