a) Four charges, Q, Q2, Q3 and Q4 are moving in space. Cartesian coordinate system is used to describe the space. Find the total force on charge Q4 [nC] exerted by the other three charges Q1, Q2 and Q3. Charges Q, Q3 and Q4 are positive, while Q2 is negative. At the instance of observation, charge Q4 is located at point (a, 0, 0), and is moving at velocity V4 = 5 km/s. The other three charges are moving at velocities V, V2, and v3, and have the following coordinates at the instance of observation: Q = 5Q4; located at point (0, a, 0), and is moving at velocity v = Q2 = - 5j m/s Q4; located at point (0, 0, 0), and is moving at velocity v = Q3 = 2Q4; located at point (0, 0, a), and is moving at velocity v3 = Values of the charge Q4 and distance a are given in Table 1. i. Draw the picture of the problem. ii. State the governing equations you use. 10j m/s -10j m/s