It takes 275n to set a stationary 77.3 crate in motion. what is the coefficient of static friction?

Note: I'm assuming the data 77.3 is the mass of the crate.

Explanation:

The coefficient of static friction, called \mu_s is the ratio between the force needed to start moving an object above a rough surface (Fr), and the normal force the surface exerts on the object (N).

The normal force is numerical equivalent to the weight of the body if no other external forces are acting.

The mass of the crate is m=77.3 Kg, thus its weight and normal force is:

Now we calculate the coefficient:

a and c

c is 100% but i am confused in a

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2