Determine the volume contraction of a solid copper cube, 10 cm on an edge, when subjected to a hydraulic pressure of ⁶ Pa.
The volume contraction of the solid copper cube is ⁻⁸ m³ (or 0.05 cm³).
Explanation
This numerical problem from NCERT Chapter 8 (Mechanical Properties of Solids) applies the concept of bulk modulus. The bulk modulus (B) relates hydraulic pressure to volumetric strain through the relation B = -P/(ΔV/V). The negative sign indicates volume decreases under pressure. The original volume of the cube is V = L³ = (10 cm)³ = 1000 cm³ = 10⁻³ m³. Using the bulk modulus of copper (B = ⁹ Pa from NCERT material property tables), the volume contraction is calculated.
Solution Steps
Step 1: Calculate original volume: V = L³ = (0.1 m)³ = 10⁻³ m³
Step 2: Apply bulk modulus formula rearranged for volume change: ΔV = P × V / B
Step 3: Substitute values: ΔV = (⁶ Pa × 10⁻³ m³)/(⁹ Pa)
Step 4: Solve: ΔV = ³/(⁹) = ⁻⁸ m³ = 0.05 cm³