question_answer 14)

Two bodies of masses 10 kg and 20 kg respectively kept on a smooth, horizontal surface are tied to the ends of a light string. A horizontal force F = 600 N is applied to (i) B (ii) A along the direction of string. What is the tension in the string in each case ?  

Answer:

Here   Let T be the tension in the string and a be the acceleration produced in the system, in the direction of applied force F. Then . (i) Suppose the pull F is applied on the body B of mass 20 kg, as shown in Fig. 5.12S(a). Let  be the tension in the string. As  is the only force acting on mass 10 kg, so .   (a) (b) Fig. 5.128   (ii) When the pull F is applied on body A of mass 10 kg [Fig. 5.128(b)] tension in the string will be . Clearly, the tension depends on which mass end the pull is applied.