Ajet takes 7 hours to travel a distance of 5586mi against the wind. the return trip takes 6 hours with the wind. what is the rate of the jet in still air and what is the rate of the wind?

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?

Materials will have different energies associated with the electrons inside them. this is related to how strongly bound they are by their work function. if we sandwich a material with a very low energy between two materials with a high energy, we create a trap for an electron. if this trap is very narrow in one direction in comparison to the others, this is approximately a 1-dimensional box that confines the electron. what is the lowest energy of an electron in the box if the thinnest direction across the materials is 4.81 nm?

Ideal meters problem. what internal resistance is ideal for a voltmeter? what internal resistance is ideal for an ammeter?