If a tree falls in the middle of the woods and nobody is around to hear it, does it make a sound?

The diagram shows a boulder rolling down a hill into a valley and then up the opposite hill. at which position does the boulder have the greatest kinetic energy? a b c d

Which statements did both aristotle and ptolemy assume? check all that apply.

The two most prominent wavelengths in the light emitted by a hydrogen discharge lamp are 656(red) and 486 (blue). light from a hydrogen lamp illuminates a diffraction grating with 500 lines per mm, and the light is observed on a screen 1.50 behind the grating. what is the distance between the first-order red and blue fringes?