How to find the maximum force of static friction?

Question

anonymous · Answer

this is the problem if it helps; 
Your dog sleeps on the floor. He has a mass of 14 kg. The coefficient of static friction between him and the floor is 0.3, and the coefficient of kinetic friction is 0.25.

anonymous · Answer

0.3 . 14 . 10 = max static force

anonymous · Answer

you mean .3x12x10? 
& where did the 10 come from? @divu.mkr

unklerhaukus · Answer

f=µmgcosθ

anonymous · Answer

coefficient of friction. Normal force 
Normal force = mass * 10 (accel due to earth)

anonymous · Answer

so if i was  sliding the dog across the floor at a speed of 2 m/s. How would i solve for the force of kinetic friction acting on the dog? @divu.mkr

unklerhaukus · Answer

use the kinetic coefficient if the object is moving

anonymous · Answer

static friction is used when the object is not moving...so if the object is moving then v'll use kinetic friction and its almost same as static f= (coefficient of kinetic friction)*normal force

anonymous · Answer

i know the normal force is 137.2, 
so would i just do 137.2X.25? @divu.mkr @UnkleRhaukus

unklerhaukus · Answer

yes

anonymous · Answer

yep

anonymous · Answer

i got the normal force by doing
 mxg 
14x9.8 
=137.2  
is that correct?

anonymous · Answer

yess

unklerhaukus · Answer

the floor is flat so θ=0,  cosθ=1

so yeah the normal force is equal to the weight