Hi, i have a set of physics questions which I really don't understand how to sol them I would really appreciate the help

27.5 Two charges O, and 22 are placed (f) a distance Ro apart. At this time the mag- nitude of the force between the charges (g is Fo. Answer the following question in terms of (h Ro or Fo. (i) (a) If the separation between charges Q1 and @2 is changed to R where R = 3Ro what is the force between the two charges now? (b) If the charge @1 is replaced by a 2 charge Q3 where @3 = 20, then what is the force F between the two charges now? (c) What separation R between the charges Q1 and Q2 would result in a force where F = - Fo? (d) What separation R between the charges Q3 and 22 would result in a force F which has the same mag- nitude as Fo? (e) If the separation between charges Q1 and Q2 is changed to R where R = 3 Ro and @1 is replaced by the charge Q? what is the force between the two charges now?27.12 Four charges are arranged in a square as shown in Figure 27.15. What is the net force on a fifth charge @ placed in the middle of the square where\fld the +2 C chalo 27.25 Two charges, CA and OB, are sepa- rated by a distance x. If we double the dis- tance between the charges and triple the magnitude of charge A, what happens to the magnitude of the force that charge A exerts on charge B? What happens to the Fig magnitude of the force that charge B ex- ma the erts on charge A? 27.26 A mad scientist invents a de- vice that is able to teleport every electron 2 in their body to the center of the Earth u (6.37x10 m below). We can make the as- sumption that the human body is mostly water with a bit of carbon and as such there will be about 3.2 x 1026 electrons per kilogram of body. If the mad scientist, who weighs 65 kg is so unwise as to actu- ally use this device on himself what will the magnitude of the attraction between his body (stripped of all electrons) and all the electrons newly deposited at the cen- arge ter of the Earth? (How does this compare m a with the gravitational attraction between the mad scientist and the Earth?)27.11 Four charges are arranged in a square as shown in Figure 27.14. What is the net force on a fifth charge @ placed in the middle of the square where 0.5 m +4 UC +4 uC 0.5 m +4 UC +4 uC Figure 27.14 (a) Q = +1 uC (b) Q = -1 UC27.20 What is the electric field in the middle of the square in Figure 27.15