Asphere with radius r is centered at the origin, an infinite cylinder with radius r has it axis along the z-axis, and an infinite slab with thickness 2r lies between the planes z=âr and z=r. the uniform charge volume densities of these objects are ïsph, ïcyl, and ïslab respectively. the objects are superposed on top of each other; the densities add where the objects overlap. how should the three densities be related so that the electric field is zero everywhere throughout the volume of the sphere?

Aresearcher plans to conduct a test of hypotheses at the 1% significance level. she designs her study to have a power of 0.90 at a particular alternative value of the parameter of interest. the probability that the researcher will commit a type ii error for the particular alternative value of the parameter at which she computed the power is: a. 0.90. b. 0.01. c. 0.10. d. equal to 1

This problem has been solved! see the answera non-uniform fire escape ladder is 6.0m long whenextended to the icy alley below. it is held at the top by africtionless pivot, and there is neglibible frictional force fromthe icy surface at the bottom. the ladder weighs 250n, and it'scenter of gravity is 2.0m along the ladder from the bottom. amother and child of total weight 750n are on the ladder 1.5m fromthe pivot. the ladder makes an angle θ with the horizontal. find the magnitude and direction ofa) the force exerted by the icy alley on the ladderb) the force exerted by the ladder on the pivotc) do your answers in part a and b depend on the angle?

Arock collection comes from which part of earth?