An Ant Walks Down the Surface of a Ball

Multiple Choice

An ant walks down the surface of a ball. If the ant begins to slip when the normal force is less than one-third of the tangential component of the ant's weight, at what angle, measured from the top of the ball, does the ant begin to slip?

A) 70.5°
B) 19.5°
C) 55.0°
D) 18.4°
E) 35.2°