A car is stopped at a traffic signal. A second car rear-ends the first car. From the crush of the two vehicles, it is estimated that the second car was traveling at 15 mph when it impacted the first car. If the second car laid down 166 feet of skid marks before the crash took place, how fast was the second car traveling when its brakes were locked up

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