Q9 of 39 Page 300

Consider the situation shown in figure (14-E3). The force F is equal to the m2 g/2, If the area of cross section of the string is A and its Young Modulus Y, find the strain developed in it. The string is light and there is no friction anywhere.




Given, the force,



The free body diagram is as follows:


Here, it’s the tension in the string which is responsible for stress. Let the tension be denoting as T.


For mass we have,



—————(1)


And for mass


—————(2)


————(3)


Using (1) and (3) we get,





We know, stress,


Young’s modulus then becomes,


therefore, strain is



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