Answer
200 GeV
Work Step by Step
Use equation 32–3 to estimate the mass of the particle, using the given distance.
$$mc^2\approx\frac{hc}{2 \pi d}$$
$$\approx \frac{(6.63\times10^{-34} J \cdot s)(3.00\times10^8m/s)}{2\pi (10^{-18}m)}(\frac{eV}{1.60\times10^{-19}J})$$
$$\approx2\times10^{11}eV=200GeV$$
This is of the same order of magnitude as the mass of the $W^{\pm}$, 80 GeV.
