5. the drawing shows a negative charge ( q 1 ) and a positive charge ( q 2 ) fixed to a circle. at the center of the circle they produce a net electric field that is directed along the horizontal axis. determine the ratio q 1 / q 2 of the charges if α=27.0° and β=64.0°.

Select for each of the following statements whether it is correct or incorrect. (a) in an isothermal expansion of an ideal gas. (b) the temperature remains constant. (b) the pressure remains constant. (c) there is work done by the gas. (d) there is heat added to the gas. (e) the change in internal energy equals zero.