Steel bar of 40 mm × 40 mm square cross section is subjected to an axi...
Given Data:
- Cross-sectional area of the steel bar: 40 mm × 40 mm
- Axial compressive load: 200 Newton
- Length of the bar: 2 meters
- C (modulus of elasticity) = 200 GPa (giga Pascal)
Calculating the Cross-sectional Area:
The given dimensions of the square cross section are 40 mm × 40 mm. To calculate the cross-sectional area, we use the formula:
Area = Length × Width
Area = 40 mm × 40 mm = 1600 mm²
Converting Cross-sectional Area to Square Meters:
Since the load is given in Newtons and the length is given in meters, it is necessary to convert the cross-sectional area from square millimeters (mm²) to square meters (m²). There are 1,000,000 mm² in 1 m².
Area = 1600 mm² ÷ 1,000,000 = 0.0016 m²
Calculating the Stress:
The stress in the bar can be calculated using the formula:
Stress = Load ÷ Area
Stress = 200 N ÷ 0.0016 m² = 125,000 N/m²
Converting Stress to Pascals:
Since the modulus of elasticity (C) is given in giga Pascal (GPa), the stress needs to be converted from Newton per square meter (N/m²) to Pascal (Pa). There are 1,000,000,000 Pa in 1 GPa.
Stress = 125,000 N/m² ÷ 1,000,000,000 = 0.000125 GPa
Calculating the Contraction:
The contraction or strain in the bar can be determined using Hooke's Law. Hooke's Law states that strain is directly proportional to stress.
Strain = Stress ÷ Modulus of Elasticity
Strain = 0.000125 GPa ÷ 200 GPa = 0.000000625
The contraction of the bar can be calculated using the formula:
Contraction = Strain × Original Length
Contraction = 0.000000625 × 2 m = 0.00000125 m
Therefore, the contraction of the steel bar will be 0.00000125 meters.
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