physics, newtons law, woman pulling bag?

Question

A woman at an airport is towing her 23.0 kg suitcase at constant speed by pulling on a strap at an angle of θ above the horizontal. She pulls on the strap with a 36.5 N force, and the friction force on the suitcase is 20.0 N.

(b) What angle does the strap make with the horizontal?

(c) What normal force does the ground exert on the suitcase?

Answer 1

So the horizontal component of her pulling force must equal to the friction force on the suitcase of 20.0 N, such that the 23.0 kg suitcase may move at a constant speed :
36.5*cosθ = 20.0
θ = arc cos(20.0/36.5) = 0.991 (radian)
the normal force the ground exert on the suitcase is the difference of the weight of the suitcase and the woman's lifting force on the suitcase via the strap:
23.0*g - 36.5sinθ = 195(N)

Answer 2

1