question_answer 26)

A 1 kg block situated on a rough incline is connected to a spring of spring constant 100 Nm~1 as shown in Fig. 6.54(a). The block is released from rest with the spring in the unstretched position. The block moves 10 cm down the incline before coming to rest. Find the coefficient of friction between the block and the incline. Assume that spring has negligible mass and the pulley is frictionless.     Fig. 6.54  

Answer:

Here Clearly, from Fig. 6.54(b), we have   Net force on the block down the incline   Distance moved, x = 10 cm = 0.1 m In equilibrium                               Work done = P.E. of stretched spring or           or   or                                       .