Answer:
Coefficient of friction, 
Explanation:
Given that,
Spring constant of the spring, k = 105 N/m
Mass of the block, m = 2 kg
The compression in the spring, x = 0.1 m
Let
is the coefficient of kinetic friction between the horizontal surface and the block. The frictional force is balanced by the restoring force in the spring such that,




So, the coefficient of kinetic friction between the horizontal surface and the block is 0.535. Hence, this is the required solution.