A60-kg woman stands on the very end of a uniform board, which is supported one-quarter of the way from one end and is balanced. what is the mass of the board?

a. 60 kg
b. 30 kg
c. 20 kg
d. 15 kg
e. 120 kg

You are your friend move a new refrigerator into his kitchen. you apply a horizontal force of 252 n in the negative x direction to try and move the 56 kg refrigerator. the coefficient of static friction is 0.61. (a) how much static frictional force does the floor exert on the refrigerator? give both magnitude (in n) and direction. magnitude n direction (b) what maximum force (in n) do you need to apply before the refrigerator starts to move?