An object with a mass of # 18 kg# is lying on a surface and is compressing a horizontal spring by #40 cm#. If the spring's constant is # 4 (kg)/s^2#, what is the minimum value of the surface's coefficient of static friction?

1 Answer
Dec 28, 2017

The coefficient of static friction is #=0.01#

Explanation:

The mass is #m=18kg#

The compression of the spring is #x=0.4m#

The spring constant is #k=4kgs^-2#

The reaction of the spring is #R=kx=4*0.4=1.6N#

The acceleration due to gravity is #g=9.8ms^-2#

The normal reaction of the object is #N=mg=18*9.8=176.4N#

The coefficient of static friction is

#mu_s=R/N=1.6/176.4=0.01#