What Is the Wavelength of a Photon Having the Same $7.5 \mathrm {~km} / \mathrm { s }$

Short Answer

What is the wavelength of a photon having the same momentum as an electron that is traveling at $7.5 \mathrm {~km} / \mathrm { s }$ ? $\left( h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } , m _ { \text {electron } } = 9.11 \times 10 ^ { - 31 } \mathrm {~kg} \right)$