A small block with mass $0\mathrm{.}0500$ kg slides in a vertical circle of radius $0\mathrm{.}500$ m on the inside of a circular track. During one of the revolutions of the block, when the block is at the bottom of its path, point A $,$ the magnitude of the normal force exerted on the block by the track has magnitude $3\mathrm{.}80$ N $.$ In this same revolution, when the block reaches the top of its path, point B $,$ the magnitude of the normal force exerted on the block has magnitude $0\mathrm{.}690$ N $.$