You wish to move a heavy box on a rough floor. the coefficient of kinetic friction between the box and the floor is 0.9. what is the best way to reduce the force of friction between the box and the floor while the box is moving? a. push or pull the box with a force parallel to the floor. b. pull the box with a force directed up at an angle of 30â° from the horizontal. c. push the box with a force directed down at an angle of 30â° from the horizontal. d. the coefficient of friction does not change so the force of kinetic friction acting on the block must be constant e. both b and c result in the same force of friction.