An object with a mass of # 2 kg# is lying still on a surface and is compressing a horizontal spring by #70 c 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
Apr 23, 2017

The coefficient of static friction is #=0.11#

Explanation:

The force of friction is

#F_r=k*Deltax#

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

The distance is #Deltax=0.70m#

Therefore,

#F_r=3*0.70=2.1N#

The coefficient of static friction is

#mu_k=F_r/N#

The normal force is #N=mg=(2g) N#

So,

#mu_k=2.1/(2g)=0.11#