A rock climber is going up a narrow space between two vertical rocks. The distance between the rocks allows the climber to brace herself using friction, where her feet are flat and in contact with one rock to the left, and her legs are straight horizontal and her back is flat against a rock on the right. The coefficient of static friction between her shoes and the rock on the left is 1.2, and between the rock at right and her back is 0.8. The climber relaxes until she is on the verge of slipping on both sides. (a) Draw a FBD for the climber
(b) What fraction of her weight is supported by the frictional force on her shoes?

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants