Question

Bob is pulling a 30kg filing cabinet with a force of 200n , but the filing cabinet refuses to move. the coefficient of static friction between the filing cabinet and the floor is 0.80.

what is the magnitude of the friction force on the filing cabinet?
express your answer to two significant figures and include the appropriate units.

Answer 1

The cabinet is being pulled with 200N and is being rested by a force equal to 200N. That is why it is not being moved.


Although the force of static friction can equal Fk=µs*F=m*g*µs=(30kg)*(9.8m/s^2)*(0.80)=235 N. It is not resisting the 200N force with 235N. Imagine if you pushed something with 200N and it pushed you back with 235N, especially a cabinet. You would think that the cabinet was alive.