An object with a mass of #7 kg# is lying still on a surface and is compressing a horizontal spring by #5/4 m#. If the spring's constant is #3 (kg)/s^2#, what is the minimum value of the surface's coefficient of static friction?

1 Answer
Dec 17, 2017

Answer:

The coefficient of static friction is #=0.055#

Explanation:

The mass is #m=7kg#

The compression of the spring is #x=5/4m#

The spring constant is #k=3kgs^-2#

The reaction of the spring is #R=kx=3*5/4=15/4=3.75N#

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

The normal reaction of the object is #N=mg=7*9.8=68.6N#

The coefficient of static friction is

#mu_s=R/N=3.75/68.6=0.055#