You want to calculate how long it takes a ball to fall to the ground from a height of 20 m. Which equation can you use to calculate the time? (Assume
no air resistance.)

Which of the choices are parts of an atom? select all that apply. a.) compound b.) electron c.) neutron d.) molecule e.) photon f.) proton g.) element

Acid precipitation chemically weathering a 5.0-kg limestone rock . which coukd be the result ?

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?