An airplane is flying through a thundercloud at a height of 2010 m. (A very dangerous thing to do because of updrafts, turbulence, and the possibility of electric discharge.) If there is a charge concentration of 46.9 C at height 4090 m within the cloud and −59.7 C at height 570 m, what is the magnitude of the electric field E at the aircraft? The Coulomb constant is 8.98755 × 109 N · m2 /C 2 . Answer in units of V/m.

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.