Encuentra la velocidad que debe tener un satélite artificial para entrar en órbita circular alrededor de la tierra, exactamente sobre su superficie

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

Which atomic model was proposed as a result of j. j. thomson’s work?

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?