Which is one use of lasers?

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

A2k pendulum has a speed of 1 m/s at a height of 1/2 meter

Most of the volume of an atom is occupied by the