Question

Your refrigerator has a mass of 120.0 kg, including the food in it. It is standing in the middle of your kitchen, and you need to move it. The coefficients of static and kinetic friction between the fridge and the tile floor are 0.48 and 0.33, respectively. What is the magnitude of the force of friction acting on the fridge, if you push against it horizontally with a force of each magnitude?

(a) 300 N


(b) 500 N


(c) 700 N

Answer 1

maximum firction foce = * m*g =0.48*120*9.8 = 564.48 N

so to move your refrigerator  u need to supply at least 564.48 N force so

in case of a and b it will not move so the friction force will be equal to the applied force which is

incase of a = 300 N

in case of b = 500 N

in case of c because applied force > 564.48 N so now kinetic friction will work so  

friction force in case of c = 0.33*120*9.8 = 388.08 N

let me know in comment if there is any problem or doubt