A cylindrical specimen of a nickel alloy having an elastic modulus of 207 GPa (30 * 106 psi) and an original diameter of 10.2 mm (0.40 in.) experiences only elastic deformation when a tensile load of 8900 N (2000 lbf ) is applied. Compute the maximum length of the specimen before deformation if the maximum allowable elongation is 0.25 mm (0.010 in.).

Respuesta :

Answer:

The maximum length of specimen is 0.475 m

Explanation:

Given :

Maximum elongation [tex]\Delta l = 0.25 \times 10^{-3}[/tex] m

Tensile force [tex]F = 8900[/tex] N

Diameter [tex]d =10.2 \times 10^{-3}[/tex] m

Elastic modulus [tex]E = 207 \times 10^{9}[/tex] Pa

So area of cylindrical specimen is given by,

   [tex]A = \pi \frac{d^{2} }{4}[/tex]

From the formula of elongation,

   [tex]\frac{F}{A} = \frac{\Delta l E}{l}[/tex]

Where [tex]l =[/tex] maximum length of specimen,

  [tex]l = \frac{\Delta l EA}{F}[/tex]

  [tex]l = \frac{\Delta l \pi E d^{2} }{4F}[/tex]

Put the value and find maximum length,

[tex]l = \frac{0.25 \times 10^{-3} \times 207 \times 10^{9} \times \pi (10.2 \times 10^{-3}) ^{2} ) }{4 \times 8900}[/tex]

[tex]l = 0.475[/tex] m