posted by John .
A chair of mass 15.5 is sitting on the horizontal floor; the floor is not frictionless. You push on the chair with a force = 38.0 that is directed at an angle of 42.0 below the horizontal and the chair slides along the floor.Use Newton's laws to calculate the normal force that the floor exerts on the chair.
You have not mentioned the units in the problem - I trust the mass is 15.5 Kg and Force =38.0 N.
Fx= 38*Cos42 .....in hor. direction
Fy= 38*Sin42 .....in vertical downward direction
For equilibrium in vertical dir.-
Normal force N = mg+Fy
N=15.5*9.8 + 38*Sin42
=151.9 + 25.4