A small sphere with mass m carries a positive charge q and is attached to one end of a silk fiber of length L. The other end of the fiber is attached to a large vertical insulating sheet that has a positive surface charge density σ. Assume that the sphere is in equilibrium and find the angle that fiber makes with the vertical sheet.

Observations show that interstellar clouds can have almost any shape and

An electron is trapped at a defect in a crystal. the defect may be modeled as a one-dimensional, rigid-walled box of width 1.00 nm. (a) sketch the wavefunctions and probability densities for the n 1 and n 2 states. (b) for the n 1 state, nd the probability of nding the electron between x1 0.15 nm and x2 0.35 nm, where x 0 is the left side of the box. (c) repeat (b) for the n 2 state. (d) calculate the energies in electron volts of the n 1 and n 2 states

The diagram shows a boulder rolling down a hill into a valley and then up the opposite hill. at which position does the boulder have the greatest kinetic energy? a b c d