Answer
$\lambda = 2.43\times 10^{-12}~m$
Work Step by Step
In part (a), we found that $p = 0.511~MeV/c$
We can find the wavelength:
$p = \frac{h}{\lambda}$
$\lambda = \frac{h}{p}$
$\lambda = \frac{hc}{0.511~MeV}$
$\lambda = \frac{(6.63\times 10^{-34}~J\cdot s)(3.0\times 10^8~m/s)}{(0.511\times 10^6~eV)(1.6\times 10^{-19}~J/eV)}$
$\lambda = 2.43\times 10^{-12}~m$
