A car travels past a sign at 8:52 pm it travels at a constant speed 1,000 meters down the road and gets to another stop sign at 8:57 pm. What was the car's speed between the signs?

Identify the theory that can be used to explain each phenomenon. answers diffraction: wave theory interference: wave theory reflection: both particle and wave theories refraction: both particle and wave theories

Which of the choices are parts of an atom? select all that apply. a.) compound b.) electron c.) neutron d.) molecule e.) photon f.) proton g.) element

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.