A 1.5-kg block sliding on a rough horizontal surface is attached to one end of a horizontal spring (k = 200 N/m) which has its other end fixed. If this system is displaced 20 cm horizontally from the equilibrium position and released from rest, the block first reaches the equilibrium position with a speed of 2.0 m/s. What is the coefficient of kinetic friction between the block and the horizontal surface on which it slides?
A) 0.34
B) 0.24
C) 0.13
D) 0.44
E) 0.17

Question

Quizplus · Accepted Answer

Explanation:The work done by the spring in bringing the block to the equilibrium position is equal to the work done by the friction in bringing the block to rest. Therefore,$$1/2kx^2=\mu_kmgx$$$$1/2(200)(0.2)^2=\mu_k(1.5)(9.8)(0.2)$$$$\mu_k=0.34$$

A 15-Kg Block Sliding on a Rough Horizontal Surface Is Attached