You are helping your friend move a new refrigerator into his kitchen. You apply a horizontal force of F-(+178i - 174k) N to try and move the 64.0-kg refrigerator. The coefficient of static friction is 0.610. (a) How much static frictional force does the floor exert on the refrigerator? Express your answer in vector form. N (b) What magnitude of maximum force do you need to apply before the refrigerator starts to move? N