Agas powered model airplane has a mass of 2.50 kilograms. a student exerts a force on a cord to keep the airplane flying around her at a constant speed of 18.0 meters per seond in a horizontal, circular path with a radius of 25.0 meters. what is the magnitude of the centripetal force exerted on the air plane to keep it moving in this circular path

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