White light is observed when light of wavelengths strikes the retina

Hydrogen and helium are both members of?

In order to do work, the force vector must be question 1 options: in a different direction than the acceleration vector. in a different direction than the displacement vector. in the same direction as the displacement vector and the motion. in the same direction as the acceleration vector.

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