Each of three blocks P, Q and R shown in figure has a mass of 3 kg. Each of the wire A and B has cross-sectional area 0.005 cm² and Young’s modulus 2 × 10¹¹ N m⁻². Neglecting friction, the longitudinal strain on wire B i $s _____$ × 10⁻⁴. (Take g = 10 m/s²)

Question

G1 Physics · Accepted Answer

Image For the three-block system: a = 10/3 m/s² For block R: 30 - T₁ = 3a 30 - T₁ = 10 T₁ = 20 N Area of wire B: A = 0.005 cm² = 0.005 × 10⁻⁴ m² = 5 × 10⁻⁷ m² Stress: = T₁/A = 20/(5 × 10⁻⁷) = 4 × 10⁷ N/m² Strain = Stress/Y = (4 × 10⁷)/(2 × 10¹¹) = 2 × 10⁻⁴ Therefore, answer = 2

Each of three blocks P, Q and R shown in figure has a mass of 3 kg. Each of the wire A and B has cross-sectional area 0.005 cm² and Young’s modulus 2 × 10¹¹ N m⁻². Neglecting friction, the longitudinal strain on wire B i s _____ × 10⁻⁴. (Take g = 10 m/s²)