Question

A person pushes on a 61 kg refrigerator by a horizontal force of 257 N. (Assume the push is in the +x-direction.)

(a) If the coefficient of static friction is 0.60, what are the magnitude (in N) and the direction (in degrees counterclockwise from the +x-axis) of the force of the static friction?

magnitude:____ N

direction:_______° counterclockwise from the +x-axis

Does the person move the refrigerator?

1. Yes

2. No    

(b) What is the magnitude (in N) of the largest push that the person can apply to the refrigerator just before it begins to move?

________ N

Answer 1

A. Applied force= 257 N

Maximum force required to move the block= umg= 0.6*61*9.8

Fmax= 358.68 N

So block doesn't move when we applied 257 N force.

Static friction= 257 N

Direction= 180 degree from +ve x axis

B. Largest push= 358.68 N (fmax as calculated in first part)