1) X-rays produced in the dentist’s office may have a wavelength of 0.32 nm. What is the frequency of these rays?
2) The distance to the Moon can be found with the help of mirrors left on the Moon by astronauts. A pulse of light is sent to the Moon and returns to Earth in 2.562 s. Using the measured value of the speed of light to the same precision, calculate the distance from Earth to the Moon
frequency (for any wave) = speed / wavelength = 3E8 / 0.32 E-9 = 9.375E17 Hz or 1/s
speed = distance / time , distance = 3.84 E8 m, remember the time is round trip.