Represent the energy transformations in kinetic energy, compression force and tension force involved in the impact of the "bullet" on the bulletproof vest?

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Why don't you see your reflection in water with waves or repples

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?