Physics (Stress & Strain)

A steel bar has a rectangular cross section measuring 1.000cm by 2.500cm and is 8.100m in length. A load of 150000.000N causes the bar to extend 2.000mm. Calculate the stress and strain.

Area = l*w
= 1.000cm*2.500cm
= 2.500cm = 0.025m
= 0.025m*8.100m
= 0.2025m

Stress = Load/ Area
150000/.02025
= 740740.7407Pa
= 740.740kPa

Strain
= 0.002m/8.100m
= 0.00024691

Is this correct?

asked by Danny
  1. σ= F/A
    A=1•2.5=2.5 cm²=2.5•10⁻⁴m²
    σ= 150000/2.5•10⁻⁴=6•10⁸ N/m².

    Strain is defined as "deformation of a solid due to stress" and can be expressed as
    ε= σ/E,
    where E= Young’s modulus (Modulus of elasticity)
    For steel E=200 GPa =>
    ε= σ/E = 6•10⁸/2•10¹¹=3•10⁻³ m = 3 mm

    posted by Elena
  2. Area = lw (correct)
    =1cm x 2.5 cm
    =0.0100 cm x 0.025 cm
    =0.00025 m²
    (remember, length 8.1 does not come into the calculation of cross section area)

    Stress
    =force (in N)/area (in m²)
    =150000/0.00025 Pa
    =6×10^8 Pa
    =6×10^5 mPa
    =600,000 mPa

    Strain
    =deformation (in metres) /original length (in metres)
    =2 mm/ 8.1 m
    =0.002 m / 8.1 m
    = 2.47×10^-4
    =0.000247

    Note Elena's formula for strain
    ε=σ/E
    is also correct, except that E is not directly given in the question.
    Also, since both σ and E are in pressure units, strain is unitless.

    posted by MathMate

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics(Stress&Strain)

    A steel bar has a rectangular cross section measuring 1.000cm by 2.900cm and is 8.700m in length. A load of 189000.00N causes the bar to extend 1.500mm. Calculate the stress and strain produced. ANS 1 = kPa (3 decimal places) ANS
  2. Physics (Stress & Strain)

    A steel bar has a rectangular cross section measuring 1.000cm by 2.900cm and is 8.700m in length. A load of 189000.00N causes the bar to extend 1.500mm. Calculate the stress and strain produced. ANS 1 = kPa (3 decimal places) ANS
  3. Physics

    A steel bar has a rectangular cross section measuring 1.000cm by 2.900cm and is 8.700m in length. A load of 189000.00N causes the bar to extend 1.500mm. Calculate the stress and strain produced. ANS 1 = kPa (3 decimal places) ANS
  4. Physics

    A steel bar has a rectangular cross section measuring 1.000cm by 2.900cm and is 8.700m in length. A load of 189000.00N causes the bar to extend 1.500mm. Calculate the stress and strain produced. ANS 1 = kPa (3 decimal places) ANS
  5. Physics

    A steel bar has a rectangular cross section measuring 1.000cm by 2.900cm and is 8.700m in length. A load of 189000.00N causes the bar to extend 1.500mm. Calculate the stress and strain produced. ANS 1 = kPa (3 decimal places) ANS
  6. Physic (Stress & Strain)

    A uniform bar 1.900m in length and having a cross sectional area of 11.000cm^2 is subject to a loading of 5450.000N. this load causes an extension to the bar length of 2.420mm. Calculate the stress and the strain produced. Area =
  7. Physics (Stress & Strain)

    A uniform bar 1.900m in length and having a cross sectional area of 10.500cm^2 is subject to a loading of 5550.000N. This load causes an extension of the bar length of 1.100mm. Calculate the stress and strain produced. Stress =
  8. Physics(Stress&Strain)

    A uniform bar 1.000 meters in length and having a cross sectional area of 10.000cm^2 is subjected to a loading of 5750.000 Newtons. This load causes an extension to the bar length of 2.740mm. Calculate the stress and the strain
  9. Physics (Stress&Strain)

    A uniform bar 1.000 meters in length and having a cross sectional area of 10.000cm^2 is subjected to a loading of 5750.000 Newtons. This load causes an extension to the bar length of 2.740mm. Calculate the stress and the strain
  10. Physics

    A uniform bar 1.000 meters in length and having a cross sectional area of 10.000cm^2 is subjected to a loading of 5750.000 Newtons. This load causes an extension to the bar length of 2.740mm. Calculate the stress and the strain

More Similar Questions