Ijust need some with these im really struggling with these.

if a musical instrument such as a trumpet or flute is “flat”, should the pipe be lengthened or shortened? explain with at least 2 sentences.

explain how the diffraction of light shows that light behaves like a wave. use 3 sentences.

I can't help you with the first part but maybe this will help on the second part-

Light behaves as a wave - it undergoes reflection, refraction, and diffraction just like any wave would. Yet there is still more reason to believe in the wavelike nature of light. Continue with Lesson 1 to learn about more behaviors that could never be explained by a strictly particle-view of light.

Sorry couldn't do better

Explanation:

it doesn't. it was imagined up in the middle ages.