posted by Boxiang .
A chair of weight 75.0N lies atop a horizontal floor; the floor is not frictionless. You push on the chair with a force of F = 45.0N directed at an angle of 40.0¡ã below the horizontal and the chair slides along the floor.
Using Newton's laws, calculate n, the magnitude of the normal force that the floor exerts on the chair.
Express your answer in newtons.
first, you are adding to the normal force pushing downward.