JEE Main202430 Jan 2024Morning ShiftPhysicsMechanical Properties of SolidsActual
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 cm 2 and Young's modulus 2 × 10 11 N m - 2 . Neglecting friction, the longitudinal strain on wire B is _____ × 10 - 4 . (Take g = 10 m s - 2 )
Correct answer
0
Step-by-step solution
Acceleration of the system, a = 3 g 9 = 10 3 m s - 2 Now, for R we can write 30 - T 1 = 3 × a ⇒ T 1 = 20 N Therefore, strain developed in wire B , strain = stress Y = T 1 A Y = 20 0 . 005 × 10 - 4 2 × 10 11 = 2 × 10 - 4