I need help with both of these questions pls

Abeam of electrons with of wavelength of 7.5 x 10-6 m is incident on a pair of narrow rectangular slits separated by 0.75 mm. the resulting interference pattern is projected onto a screen 10.0 m from the slits. what is the separation of the interference maxima in the resulting interference pattern?

Ineed the answers for these promblems i have

Describe how the motion of a spring being pushed forward and backward is similar to the motion of air particles in a sound wave.