1. X-rays reflect from a salt crystal the planes of which are separated by 0.265 nm. The first order diffraction maximum occurs at an angle of 22.6° to the crystal planes. What is the wavelength of the x-rays?
2. A Doppler radar set, of the type commonly used by the police to detect speeders, operates at a frequency of 2.415×1010 Hz. The radar can measure automobile speeds to within 1.7 m/s. What is the smallest Doppler frequency ratio that the system must be able to detect? (express your answer in the ratio of the velocity range to that of the speed of the radar signals)