Charge and coulombs law

Please see attached diagrams for problem and question, thanks.

Charge and potential energy

two dust particles each of mass 13 ug (10^-6) are floating on a gentle stream of air. what (equal) positive charge would each dust particle have to carry in order that their electrostatic repulsion should exactly balance their gravitational attraction? what is the electrostatic potential energy of the two dust particles each carrying the charge you calculated above if they are 1.0 cm apart? what is the gravitational potential energy of the two dust particles due to their mutual gravitational attraction, at the same separation of 1.0 cm? comment on the values that you obtained above, making reference to the conventions you used regarding the zeros of electrostatic and gravitational p... click for more

Magnetic field from two infinitely long wires

Two wires of infinite length are placed at a distance D = 10cm on opposite sides of a point O, both wires carry the same current of 1.0 A, in which direction must this current flow in order for the magnetic field strength at O to be non-zero. Consider a general point on the line joining the 2 wires and a distance d away from the mid point O. By summing the magnetic field due to currents of magnitude i flowing in both wires in the sense you found in (a), show that, on the line joining the two wires, the magnetic field strength is given by (see attachment for expression) An electron is traveling at 5.0 x 106 m s-1 directly into the page at the point P shown in figure 1. P is 4.0 cm fr... click for more

Help determine line-to-line voltage of a circuit.

If the line-to-neutral voltage in a three-phase Y-connected circuit is 240 volts, determine the line-to-line voltage.

Comparison of conductivity of probes in a saline solution

Probes were part way inserted through the lid of a jar containing weak saline solution. The jar containing the solution was heated through different temps. and the conductivity of the metal probes compared. Should there be attention paid to pressure (inside the jar) when trying to establish the difference in conductivity of the probes for each temperature.