JEE Main2013PhysicsMechanical Properties of SolidsActual
Two blocks of masses m and M are connected by means of a metal wire of cross-sectional area A passing over a frictionless fixed pulley as shown in the figure. The system is then released. If M =2 ~m , then the stress produced in the wire is:
Options
- A2 mg 3 ~A
- B4 mg 3 ~A
- Cmg A
- D3 mg 4 ~A
Correct answer
B. 4 mg 3 ~A
Step-by-step solution
Tension in the wire, T = ( 2 mM m + M ) g aligned Stress &= Force / Tension Area = 2 mM A ( m + M ) g &= 2( ~m 2 ~m ) g A ( m +2 ~m ) ( M =2 ~m given ) &= 4 ~m ^2 3 ~mA ~g = 4 mg 3 ~A aligned