A certain particle is sent into a uniform magnetic field, with the particle’s velocity vector perpendicular to the direction of the field. Figure 28-37 gives the period $T$ of the particle’s motion versus the inverse of the field magnitude $B$. The vertical axis scale is set by $T_{y}=40.0 \mathrm{~ns},$ and the horizontal axis scale is set by $B_{s}^{-1}=5.0 \mathrm{~T}^{-1} .$ What is the ratio $\mathrm{m} / q$ of the particle's mass to the magnitude of its charge?
(FIGURE CANT COPY)