In a crystal diffraction experiment, a beam of protons has the same de Broglie wavelength as a separate beam of lithium-6 nuclei. The lithium-6 nuclei are traveling at a speed of 3.2×104 m s−13.2 \times 10^4 \text{ m s}^{-1}3.2×104 m s−1.
Calculate the speed of the protons in the beam.
Take the mass of a proton to be 1.67×10−27 kg1.67 \times 10^{-27} \text{ kg}1.67×10−27 kg and the mass of a lithium-6 nucleus to be 9.98×10−27 kg9.98 \times 10^{-27} \text{ kg}9.98×10−27 kg.
