4. Examine the charge distribution in the following diagram. (9 marks) N - 4.0 x 10-5 C 24cm 24cm +2.0 x 105 C - 4.0 x 10-5 C a) Determine the net electric field acting at q1, caused by q2 and q3. b) Determine the net force charge acting on 91, caused by q2 and q3. c) Determine the total electric potential energy for the charge distribution. 5. Using the two-dimensional wave interference pattern shown, a student makes the following measurements (note that diagram may no be to scale when printed). (8 marks) For the point on the second notal line (n=2), PS = 37 mm P2S2 = 46 mm For the point on the first anti-nodal line (m = 1), PS = 41mm PS = 35 mm a) Calculate the wavelength based on measurements for the point on the second nodal line. b) Calculate the wavelength based on measurements for the point on the first anti-nodal line. c) What effect would an increase in frequency have on the interference pattern? d) What effect would a decrease in the distance between the wave sources have on the interference pattern?