9. a ball with a mass of 1.2x10^-2 kg is swung in a horizontal circle at the end of a string. the string is 1.5 m long and the ball revolves at a
speed of 3.3 m/s.
a. what force does the string exert on the ball?
b. what force does the ball exert on the string?

will mark brainliest

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?