Classify which of the following is a substance: tablero salt, seawater or sand? explain how you know.

Two identical small charged spheres are a certain distance apart, and each one initially experiences an electrostatic force of magnitude f due to the other. with time, charge gradually leaks off of both spheres. when each of the spheres has lost half its initial charge, the magnitude of the electrostatic force will be

Spend time observing or thinking about events that involve matter and energy. which events can you explain? which events can’t you explain?

What is the measure of a change in an objects velocity?