Could someone check a for me and help me with b and c Thanks

Could someone check a for me and help me with b and c? Thanks!!

A thin semicircular rod has a total charge +Q uniformly distributed along it. A negative point charge -Q is placed as shown. A test charge +q is placed at point C. (Point C is equidistant from -Q and from all points on the rod.) Let F_P and F_R represent the force on the test charge due to the point charge and the rod respectively. Is the magnitude of F_p greater than, less than, or equal to the magnitude of F_R? Explain how you can tell. Is the magnitude of the net force on +q greater than, less than, or equal to the magnitude of F_p? Explain. A second negative point charge -Q is placed as shown. Is the magnitude of the net electric force on +q greater than, than, or equal to the magnitude of the net electric force on +q in part b? Explain

Solution

a) you are right.

b)The charge at point \"C\" is positive, so it is being attracted to the negative point charge. It is also being repelled from the positively charged rod, so Fp and Fr are in the same direction, and probably add, given the symmetry of the configuration. If they add, the net force is greater than Fp, since it includes Fp

c) Since - Q charge would cancel some force so it would be lesser.