The observed frequency increases when the source and observer approach each other and decreases when they move apart. this is called the what?
1) emission spectrum
2) doppler effect
3) wavelength

would it be plagiarism to copy and paste off of here? ?

hello,

question- which is one way that muslims scholars contributed to the scientific recolution?

answer- well you see in the religion islam the religion muslims practice there was the prophet muahmmed peace be upon him who did good things such as sit in a sertian posotion to use the toilet which then the scientist of this generation later found that it was good for you there are many more things like this.

important- if my answer was enough for you to understand mark me as brainliest you and have the best day ever!