What would the separation between two identical objects, one carrying 2 C
of positive charge and the other
2 C
of negative charge, have to be if the electrical force on each was precisely
9 N?

i think it because equal matrices have equal dimensions, only square matrices can be symmetric. for all indices and . every square diagonal matrix is symmetric, since all off-diagonal elements are zero. in linear algebra, a real symmetric matrix represents a self-adjoint operator over a real inner product space.

massxgravity x heght=weightxheight= pe

4900=490xh

h=10

i think the answer is a, hope this : )