posted by Stephanie .
A woman at an airport is towing her 20.0 kg suitcase at constant speed by pulling on a strap at an angle θ above the horizontal. She pulls on the strap with a 35.0 N force, and the friction force on the suitcase is 20.0 N.
a) What angle does the strap make with the horizontal?
b) What normal force does the ground exert on the suitcase?
(a) θ = cos^-1 (20/35) = 55 degrees
(Friction equals the horizontal component of the applied force, since it is not accelerating.)
(b) M g - 35 sin 55 = 196 - 28.7 = 167.3 N