In cities, the area in which rain water can seep into the ground is reduced. water flows over roads, then the runoff is carried out to sea through drainage systems. how does the runoff from cities affect ocean systems?
a.
ocean systems are improved by receiving more water.
b.
ocean systems are damaged with more pollutants.
c.
ocean systems are improved by the addition of nutrients.
d.
ocean systems are damaged with the loss of sediments.

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